MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Glycobiology' source. Fri, 19 Mar 2010 17:20:43 +0100 http://www.medworm.com/index.php?rid=3358290&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F485%3Frss%3D1 N-Acetylglucosaminyltransferase-IV (GnT-IV) has two isoenzymes, GnT-IVa and GnT-IVb, which initiate the GlcNAcβ1-4 branch synthesis on the Man1-3 arm of the N-glycan core thereby increasing N-glycan branch complexity and conferring endogenous lectin binding epitopes. To elucidate the physiological significance of GnT-IV, we engineered and characterized GnT-IVb-deficient mice and further generated GnT-IVa/-IVb double deficient mice. In wild-type mice, GnT-IVa expression is restricted to gastrointestinal tissues, whereas GnT-IVb is broadly expressed among organs. GnT-IVb deficiency induced aberrant GnT-IVa expression corresponding to the GnT-IVb distribution pattern that might be attributed to increased Ets-1, which conceivably activates the Mgat4a promoter, and thereafter preserved app... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358290 Fri, 12 Mar 2010 07:03:42 +0100 3358290 http://www.medworm.com/index.php?rid=3358289&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F473%3Frss%3D1 Ophiopogon japonicus is a traditional Chinese medicine used to treat cardiovascular disease. Recent studies have confirmed its beneficial properties, but not the mechanism of action. Herein, we investigate the anti-ischemic properties of a water-soluble β-d-fructan (MDG-1) from Ophiopogon japonicus, and assess the cytoprotective and proangiogenic effects of MDG-1. MDG-1 protects cardiomyocyte and microvascular endothelial cells (HMEC-1) against oxygen glucose deprivation (OGD)-induced cell death, as well as protect myocardial cells from ischemia-induced death occurring after coronary artery ligation in rats. Meanwhile, MDG-1 stimulates the differentiation of HMEC-1 cells into capillary-like structures in vitro and functions as a chemoattractant in migration assays, and promotes neovas... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358289 Fri, 12 Mar 2010 07:03:42 +0100 3358289 http://www.medworm.com/index.php?rid=3358288&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F461%3Frss%3D1 Chlamydiae contain a rough-type lipopolysaccharide (LPS) of 3-deoxy--d-manno-oct-2-ulopyranosonic acid residues (Kdo). Two Kdo trisaccharides, 2.8/2.4- and 2.4/2.4-linked, and a branched 2.4[2.8]2.4-linked Kdo tetrasaccharide occur in Chlamydiaceae. While the 2.8/2.4-linked trisaccharide contains a family-specific epitope, the branched Kdo oligosaccharide occurs only in Chlamydophila psittaci and antibodies against it will be useful in human and veterinarian diagnostics. To overcome the generation of cross-reactive antibodies that bind with high affinity to a dominant epitope formed by 2.4/2.4-linked Kdo, we immunized mice with a synthetic 2.4[2.8]-linked branched Kdo trisaccharide and used phage display of scFv to isolate recombinant antibody fragments (NH2240-31 and SAG506-01) that recog... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358288 Fri, 12 Mar 2010 07:03:42 +0100 3358288 http://www.medworm.com/index.php?rid=3358287&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F452%3Frss%3D1 A prostate-specific antigen (PSA) is widely used as a diagnostic marker for prostate cancer (PC) because of its high specificity. However, elevated serum PSA does not occur only in PC but also in benign prostatic hyperplasia (BPH). Since the structural changes of N-glycans during carcinogenesis are common phenomena, we investigated whether PC-specific N-glycans are linked to PSA. We first analyzed the carbohydrate structures of PSA derived from seminal fluid, serum of BPH and PC patients, and PC cell line, namely, LNCaP using eight lectin-immobilized columns and then with enzyme-linked immunosorbent assay (ELISA). The fraction of serum PSA from PC patients bound to both Fuc1-2Gal and βGalNAc binding Trichosanthes japonica agglutinin-II (TJA-II) column, while that from BPH patients did... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358287 Fri, 12 Mar 2010 07:03:42 +0100 3358287 http://www.medworm.com/index.php?rid=3358286&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F442%3Frss%3D1 A genomic library of bacterial strain Paenibacillus thiaminolyticus was constructed and the plasmid DNA of the clone, containing the gene encoding β-d-galactosidase with β-d-fucosidase activity, detected by 5-bromo-4-chloro-3-indoxyl β-d-galactopyranoside, was sequenced. Cells of Escherichia coli BL21 (DE3) were used for production of the enzyme in the form of a histidine-tagged protein. This recombinant fusion protein was purified using Ni-NTA agarose affinity chromatography and characterized by using p-nitrophenyl β-d-fucopyranoside (Km value of (1.18 ± 0.06) mmol/L), p-nitrophenyl β-d-galactopyranoside (Km value of (250 ± 40) mmol/L), p-nitrophenyl β-d-glucopyranoside (Km value of (77 ± 6) mmol/L), and lactose (Km value of (206 ±... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358286 Fri, 12 Mar 2010 07:03:42 +0100 3358286 http://www.medworm.com/index.php?rid=3358285&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F433%3Frss%3D1 Hirsutella rhossiliensis, a nematophagous fungus belonging to the Ascomycota, is resistant to aureobasidin A (AbA). In this fungus, the biosynthetic pathway leading to mannosylinositolphosphoceramides, which is inhibited by AbA, was not detected. Instead, this fungus contains neutral complex glycosphingolipids (GSLs) and monoglycosylceramides. Except for monoglycosylceramides, neutral GSLs share a neogala-series core structure, Galβ1–6Galβ1-Cer. Among the GSLs of H. rhossiliensis, three novel GSLs with terminal Man and Glc residues on the sugar chain were elucidated. We analyzed GSL structure using compositional sugar, fatty acid, and sphingoid analyses, methylation analysis, matrix-assisted laser desorption ionization time-of-flight/mass spectrometry (MALDI-TOF MS), and 1H... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358285 Fri, 12 Mar 2010 07:03:42 +0100 3358285 http://www.medworm.com/index.php?rid=3358284&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F420%3Frss%3D1 This study suggests that Endo FV may become similar to Endo H in substrate specificity as a result of evolutionary convergence. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358284 Fri, 12 Mar 2010 07:03:42 +0100 3358284 http://www.medworm.com/index.php?rid=3358283&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F406%3Frss%3D1 Innate immunity is the first line of defense against invading microorganisms in vertebrates and the only line of defense in invertebrates and plants. Bacterial glyco-conjugates, such as lipopolysaccharides (LPS) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN) from the cell walls of both Gram-positive and Gram-negative bacteria, and fungal and oomycete glycoconjugates such as oligosaccharides derived from the cell wall components β-glucan, chitin and chitosan, have been found to act as elicitors of plant innate immunity. These conserved indispensable microbe-specific molecules are also referred to as microbe-associated molecular patterns (MAMPs). Other glyco-conjugates such as bacterial extracellular polysaccharides (EPS) and cyclic glucan have been shown to s... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358283 Fri, 12 Mar 2010 07:03:42 +0100 3358283 http://www.medworm.com/index.php?rid=3358282&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F404%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358282 Fri, 12 Mar 2010 07:03:42 +0100 3358282 http://www.medworm.com/index.php?rid=3358281&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2F403%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358281 Fri, 12 Mar 2010 07:03:42 +0100 3358281 http://www.medworm.com/index.php?rid=3358280&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358280 Fri, 12 Mar 2010 07:03:42 +0100 3358280 http://www.medworm.com/index.php?rid=3358279&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358279 Fri, 12 Mar 2010 07:03:42 +0100 3358279 http://www.medworm.com/index.php?rid=3358278&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F4%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3358278 Fri, 12 Mar 2010 07:03:42 +0100 3358278 http://www.medworm.com/index.php?rid=3235227&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F395%3Frss%3D1 In conclusion, Siglec-7 induces nonapoptotic cell death, the signal for which is transduced by an extracellular C2-set domain. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235227 Tue, 02 Feb 2010 16:04:02 +0100 3235227 http://www.medworm.com/index.php?rid=3235226&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F381%3Frss%3D1 In this study, we characterized the glycosylation of Drosophila DG using a combination of glycosidase treatments, lectin blots, trypsin digestion, and mass spectrometry analyses. Our results demonstrated that DG extracellular domain is O-mannosylated in vivo. We found that the concurrent in vivo activity of the two Drosophila protein O-mannosyltransferases, Rotated Abdomen and Twisted, is required for O-mannosylation of DG. While our experiments unambiguously determined some O-mannose sites far outside of the mucin-type domain of DG, they also provided evidence that DG bears a significant amount of O-mannosylation within its central region including the mucin-type domain, and that O-mannose can compete with O-GalNAc glycosylation of DG. We found that Rotated Abdomen and Twisted could poten... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235226 Tue, 02 Feb 2010 16:04:02 +0100 3235226 http://www.medworm.com/index.php?rid=3235225&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F369%3Frss%3D1 Glycan arrays have enabled detailed studies of the specificities of glycan-binding proteins. A challenge in the interpretation of glycan array data is to determine the specific features of glycan structures that are critical for binding. To address this challenge, we have developed a systematic method to interpret glycan array data using a motif-based analysis. Each glycan on a glycan array is classified according to its component sub-structures, or motifs. We analyze the binding of a given lectin to each glycan in terms of the motifs in order to identify the motifs that are selectively present in the glycans that are bound by the lectin. We compared two different methods to calculate the identification, termed intensity segregation and motif segregation, for the analysis of three well-cha... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235225 Tue, 02 Feb 2010 16:04:02 +0100 3235225 http://www.medworm.com/index.php?rid=3235224&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F366%3Frss%3D1 ECODAB (the E. coli O-antigen database) has been expanded to include information about glycosyltransferases (GTs) involved in the assembly of the O-antigen polysaccharide. Similarity searches have been performed to be able to determine GT functions that have not been reported prior to this work. In addition to suggesting the function of 179 GTs, the approach leads to the prediction of part of the O-antigen structures of a number of serogroups. The procedure suggests a novel way of combining genetic information with experimental techniques in structural analysis of oligo- and polysaccharides. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235224 Tue, 02 Feb 2010 16:04:02 +0100 3235224 http://www.medworm.com/index.php?rid=3235223&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F356%3Frss%3D1 Enzyme enhancement therapy, utilizing small molecules as pharmacological chaperones, is an attractive approach for the treatment of lysosomal storage diseases that are associated with protein misfolding. However, pharmacological chaperones are also inhibitors of their target enzyme. Thus, a major concern with this approach is that, despite enhancing protein folding within, and intracellular transport of the functional mutant enzyme out of the endoplasmic reticulum, the chaperone will continue to inhibit the enzyme in the lysosome, preventing substrate clearance. Here we demonstrate that the in vitro hydrolysis of a fluorescent derivative of lyso-GM2 ganglioside, like natural GM2 ganglioside, is specifically carried out by the β-hexosaminidase A isozyme, requires the GM2 activator prot... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235223 Tue, 02 Feb 2010 16:04:02 +0100 3235223 http://www.medworm.com/index.php?rid=3235222&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F348%3Frss%3D1 In this study, the recombinant human XTP3-B fused with IgG-Fc (XTP3-B-Fc), XTP3-B without an N-terminal MRH domain fused with IgG-Fc (XTP3-B1-Fc), or XTP3-B without a C-terminal MRH domain fused with IgG-Fc (XTP3-B2-Fc) were prepared. XTP3-B-Fc and XTP3-B1-Fc bound to Lec1 cells but not to CHO, Lec2, or Lec8 cells, while XTP3-B2-Fc did not bind to any of these cells. The binding of XTP3-B-Fc and XTP3-B1-Fc to Lec1 cells was abrogated by treatment of the cells with endo-β-N-acetylglucosaminidase H, Man1,6Man or Man1,6(Man1,3)Man1,6(Man1,3)Man, or by substitution of Arg428 or Tyr457 in the C-terminal MRH domain with alanine. Arg428 and Tyr457 are homologous to amino acids that mediate glycan binding by the cation-dependent mannose-6-phosphate receptor. An immunoprecipitation experiment ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235222 Tue, 02 Feb 2010 16:04:02 +0100 3235222 http://www.medworm.com/index.php?rid=3235221&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F338%3Frss%3D1 Burkholderia kururiensis, strain M130, an endophytic diazotrophic bacterium isolated from rice roots, produces acetylated acidic exopolysaccharides which can be separated by anion exchange chromatography. These were characterized by nuclear magnetic resonance spectroscopy, methylation analysis and Smith degradation. The exopolysaccharides eluted with 0.5 M NaCl were produced when the bacterium was grown in a medium containing mannitol as the sole carbon source, and showed to be a mixture of two different polymers, composed of hepta or octasaccharide repeat units, consistent with following structure: The ability of diazotrophic Burkholderia to produce two exopolysaccharides that differ by the presence of a terminal glucosyl residue provides insight into polysaccharide function with potent... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235221 Tue, 02 Feb 2010 16:04:02 +0100 3235221 http://www.medworm.com/index.php?rid=3235220&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F322%3Frss%3D1 The bifunctional enzyme UDP-GlcNAc 2-epimerase/ ManNAc kinase (GNE/MNK), encoded by the GNE gene, catalyzes the first two committed, rate-limiting steps in the biosynthesis of N-acetylneuraminic acid (sialic acid). GNE/MNK is feedback inhibited by binding of the downstream product, CMP-sialic acid in its allosteric site. GNE mutations can result in two human disorders, hereditary inclusion body myopathy (HIBM) or sialuria. So far, no active site geometry predictions or conformational transitions involved with function are available for mammalian GNE/MNK. The N-terminal GNE domain is homologous to various prokaryotic 2-epimerases, some of which have solved crystallographic structures. The C-terminal MNK domain belongs to the sugar kinases superfamily; its crystallographic structure is solve... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235220 Tue, 02 Feb 2010 16:04:02 +0100 3235220 http://www.medworm.com/index.php?rid=3235219&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F310%3Frss%3D1 Misfolded glycoproteins are translocated from the endoplasmic reticulum (ER) into the cytoplasm for proteasome-mediated degradation. OS-9 protein is thought to participate in ER-associated glycoprotein degradation (ERAD). The recombinant biotinylated mannose 6-phosphate receptor homology (MRH) domain of human OS-9 (OS-9MRH) together with six kinds of mutated OS-9MRH were prepared and mixed with R-phycoerythrin (PE)-labeled streptavidin to form tetramers (OS-9MRH-SA). The PE-labeled OS-9MRH-SA bound to HeLaS3 cells in a metal ion-independent manner through amino acid residues homologous to those participating in sugar binding of the cation-dependent mannose 6-phosphate receptor, and this binding was greatly increased by swainsonine, deoxymannojirimycin, or kifunensine treatment. N-Acetylglu... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235219 Tue, 02 Feb 2010 16:04:02 +0100 3235219 http://www.medworm.com/index.php?rid=3235218&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F300%3Frss%3D1 In this study, human hyaluronidase-4 was demonstrated to be a CS-specific endo-β-N-acetylgalactosaminidase. This is the first demonstration of a CS hydrolase in higher organisms. The specificity of a purified recombinant form of the enzyme was investigated in detail through the characterization of degradation products. The best substrate of the CS hydrolase was the galactosaminidic linkage in the sequence of a trisulfated tetrasaccharide GlcUA(2-O-sulfate)-GalNAc(6-O-sulfate)-GlcUA-GalNAc(4-O- or 6-O-sulfate), where GlcUA and GalNAc represent d-glucuronic acid and N-acetyl-d-galactosamine, respectively. The disaccharide unit on the nonreducing side, GlcUA(2-O-sulfate)-GalNAc(6-O-sulfate) (D unit), is rich in shark fin cartilage CS-D among various CS isoforms. CS hydrolase will be a us... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235218 Tue, 02 Feb 2010 16:04:02 +0100 3235218 http://www.medworm.com/index.php?rid=3235217&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F287%3Frss%3D1 Notch is a key cell surface protein receptor that is a vital component of intercellular signaling occurring during development. The O-glucosylation of the extracellular Notch epidermal growth factor-like (EGF) repeats has recently been found to play an important role in the proper functioning of Notch in Drosophila. Previous efforts to identify the fine structure of the O-glucose-containing glycan of mammalian Notch have been hindered by limitations associated with approaches used to date. Here, we report the development of an alternative strategy that can be used to study this modification from a range of different tissues. To implement this approach, we have generated standards of the d-Xyl-1-3-d-Xyl-1-3-d-Glc trisaccharide, isomers of this structure, as well as the d-Xyl-1-3-d-Glc disac... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235217 Tue, 02 Feb 2010 16:04:02 +0100 3235217 http://www.medworm.com/index.php?rid=3235216&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F280%3Frss%3D1 Design of an envelope glycoprotein (Env)-based vaccine against human immunodeficiency virus type-1 (HIV-1) is complicated by the large number of N-linked glycans that coat the protein and serve as a barrier to antibody-mediated neutralization. Compared to normal mammalian glycoproteins, high-mannose-type glycans are disproportionately represented on the gp120 subunit of Env. These N-glycans serve as a target for a number of anti-HIV molecules that bind terminal 1,2-linked mannose residues, including lectins and the monoclonal antibody 2G12. We created a Saccharomyces cerevisiae glycosylation mutant, mnn1mnn4, to expose numerous terminal Man1,2-Man residues on endogenous hypermannosylated glycoproteins in the yeast cell wall. Immunization of rabbits with whole cells from this mutant induced... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235216 Tue, 02 Feb 2010 16:04:02 +0100 3235216 http://www.medworm.com/index.php?rid=3235215&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F270%3Frss%3D1 The innate immune response of multicellular organisms is initiated by the binding of soluble and membrane-bound host molecules including lectins to the surface of pathogenic organisms. Until recently, it was believed that the epitopes recognized by host molecules were uniquely associated with the pathogenic organisms. Hence, the term pattern recognition receptors (PRRs) was used to describe their binding specificities. However, with an expanding number of lectin classes including C-type lectins, siglecs, and galectins recognized as PRRs, it is apparent that many of the glycan epitopes recognized on foreign pathogens are present in the host and involved in cellular functions. Hence, the molecular basis for pattern recognition by lectins of carbohydrate epitopes on pathogens is in question. ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235215 Tue, 02 Feb 2010 16:04:02 +0100 3235215 http://www.medworm.com/index.php?rid=3235214&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2F269%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235214 Tue, 02 Feb 2010 16:04:02 +0100 3235214 http://www.medworm.com/index.php?rid=3235213&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235213 Tue, 02 Feb 2010 16:04:01 +0100 3235213 http://www.medworm.com/index.php?rid=3235212&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235212 Tue, 02 Feb 2010 16:04:01 +0100 3235212 http://www.medworm.com/index.php?rid=3235211&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F3%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3235211 Tue, 02 Feb 2010 16:04:01 +0100 3235211 http://www.medworm.com/index.php?rid=3133187&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F260%3Frss%3D1 We report here the discovery of the 2,6-trans-sialidase activity of a previously reported recombinant truncated bacterial 2,6-sialyltransferase from Photobacterium damsela (15Pd2,6ST). This is the first time that the 2,6-trans-sialidase activity has ever been identified. Kinetic studies indicate that 15Pd2,6ST-catalyzed trans-sialidase reaction follows a ping-pong bi-bi reaction mechanism. Cytidine 5'-monophosphate, the product of sialyltransferase reactions, is not required by the trans-sialidase activity of the enzyme but enhances the trans-sialidase activity modestly as a non-essential activator. Using chemically synthesized Neu5AcpNP and LacβMU, 2,6-linked sialoside Neu5Ac2,6LacβMU has been obtained in one-step in high yield using the trans-sialidase activity of 15Pd2,6ST. In... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133187 Thu, 31 Dec 2009 09:10:06 +0100 3133187 http://www.medworm.com/index.php?rid=3133186&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F248%3Frss%3D1 Metachromatic leukodystrophy (MLD) is a lysosomal storage disease caused by a deficiency of the lysosomal enzyme arylsulfatase A (ASA). Enzyme replacement therapy (ERT) is a therapeutic option for MLD and other lysosomal disorders. This therapy depends on N-linked oligosaccharide-mediated delivery of intravenously injected recombinant enzyme to the lysosomes of patient cells. Because of the importance of N-linked oligosaccharide side chains in ERT, we examined the composition of the three N-linked glycans of four different recombinant ASAs in a site-specific manner. Depending on the culture conditions and the cell line expressing the enzyme, we detected a high variability of the high-mannose-type N-glycans which prevail at all glycosylation sites. Our data show that the composition of the ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133186 Thu, 31 Dec 2009 09:10:06 +0100 3133186 http://www.medworm.com/index.php?rid=3133185&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F235%3Frss%3D1 N-Glycosylation is an important post-translational modification that occurs in many secreted and membrane proteins in eukaryotic cells. Golgi -mannosidase I hydrolases (MANI) are key enzymes that play a role in the early N-glycan modification pathway in the Golgi apparatus. In Arabidopsis thaliana, two putative MANI genes, AtMANIa (At3g21160) and AtMANIb (At1g51590), were identified. Biochemical analysis using bacterially produced recombinant AtMANI isoforms revealed that both AtMANI isoforms encode 1-deoxymannojirimycin-sensitive -mannosidase I and act on Man8GlcNAc2 and Man9GlcNAc2 structures to yield Man5GlcNAc2. Structures of hydrolytic intermediates accumulated in the AtMANI reactions indicate that AtMANIs employ hydrolytic pathways distinct from those of mammalian MANIs. In planta, A... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133185 Thu, 31 Dec 2009 09:10:06 +0100 3133185 http://www.medworm.com/index.php?rid=3133184&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F224%3Frss%3D1 Polysulfated carbohydrates such as heparin (HP) and heparan sulfate (HS) are not easily amenable to usual ultraviolet matrix-assisted laser desorption/ionization-mass spectrometry (UV-MALDI)-MS analysis due to the thermal lability of their O- and N-SO3 moieties, and their poor ionization efficiency with common crystalline matrices. Recently, ionic liquid matrices showed considerable advantages over conventional matrices for MALDI-MS of acidic compounds. Two new ionic liquid matrices (ILMs) based on the combination of 2-(4-hydroxyphenylazo)benzoic acid (HABA) with 1,1,3,3-tetramethylguanidine and spermine were evaluated in the study herein. Both ILMs were successfully applied to the analysis of synthetic heparin oligosaccharides of well-characterized structures as well as to heparan sulfate... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133184 Thu, 31 Dec 2009 09:10:06 +0100 3133184 http://www.medworm.com/index.php?rid=3133183&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F215%3Frss%3D1 SMMC-7721 hepatocellular carcinoma cells (HCC) were incubated with fucosylated glycoproteins that had been isolated from retinoic acid-treated cells by affinity chromatography. HCC migration was significantly inhibited by AAL- and LCA-glycoproteins. Glycopeptides, obtained by digestion of the glycoproteins with trypsin and papain, were found to have a similar inhibitory effect on HCC migration as the corresponding glycoproteins. The inhibitory actions of the glycoproteins were almost abolished after digestion with -L-1,3/4- or -L-1,2-fucosidase. Induction of HCC migration with chemokines including interleukin-8 (IL-8), lymphotactin, monocyte chemoattractant protein-1, and stroma cell-derived factor-1 was examined and IL-8 was found to be the most potent. Interestingly, the isolated glycopr... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133183 Thu, 31 Dec 2009 09:10:06 +0100 3133183 http://www.medworm.com/index.php?rid=3133182&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F207%3Frss%3D1 Immunochemical analysis of the Yokenella regensburgei lipopolysaccharides (LPS) indicated the presence of the core oligosaccharide-related immunotypes among the investigated strains. The structure of the core oligosaccharide segment of the Y. regensburgei LPS has been investigated using chemical methods, mass spectrometry, and 1H, 13C NMR spectroscopy. It was concluded that the core oligosaccharides of the strains PCM 2476 and PCM 2477 are composed of an undecasaccharide. The combined data revealed two immunotypes of the core oligosaccharide recognized by antibodies against the whole bacterial cells. The structural differences between the core oligosaccharides are limited to the outermost terminal hexopyranose residue. In the core oligosaccharide of the strain PCM 2476, it was identified a... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133182 Thu, 31 Dec 2009 09:10:06 +0100 3133182 http://www.medworm.com/index.php?rid=3133181&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F199%3Frss%3D1 Changes in mucin protein expression and in glycosylation are common features in pre-neoplastic lesions and cancer and are therefore used as cancer-associated markers. De novo expression of intestinal mucin MUC2 and cancer-associated sialyl-Tn antigen are frequently observed in intestinal metaplasia (IM) and gastric cancer. However, despite that these antigens often co-localize, MUC2 has not been demonstrated to be a carrier of sialyl-Tn. By using the in situ proximity ligation assay (in situ PLA), we herein could show that MUC2 is a major carrier of the sialyl-Tn antigen in all IM cases and in most gastric carcinoma cases. The requirement by in situ PLA for the presence of both antigens in close proximity increases the selectivity compared to measurement of co-localization, as determined b... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133181 Thu, 31 Dec 2009 09:10:06 +0100 3133181 http://www.medworm.com/index.php?rid=3133180&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F187%3Frss%3D1 Bacterial sialyltransferases (STs) from marine sources were characterized using glycosphingolipids (GSLs). Bacterial STs were found to be β-galacotoside STs. There were two types of STs: (1) ST obtained from strains such as ishi-224, 05JTC1 (#1), ishi-467, 05JTD2 (#2), and faj-16, 05JTE1 (#3), which form 2-3 sialic acid (Sia) linkages, named 2-3ST, (2) ST obtained from strains such as ISH-224, N1C0 (#4), pda-rec, 05JTB2 (#5), and pda-0160, 05JTA2 (#6), which form 2-6 Sia linkages, named 2-6ST. All STs showed affinity to neolacto- and lacto-series GSLs, particularly in neolactotetraosyl ceramide (nLc4Cer). No large differences were observed in the pH and temperature profiles of enzyme activities. Kinetic parameters obtained by Lineweaver–Burk plot analysis showed that #3 and #4 S... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133180 Thu, 31 Dec 2009 09:10:06 +0100 3133180 http://www.medworm.com/index.php?rid=3133179&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F175%3Frss%3D1 Heparan sulfates (HS) bind a diversity of protein ligands on the cell surface and in the extracellular matrix and thus can modulate cell signaling. The state of sulfation in glucosamines and uronic acids within the chains strongly influences their binding. We have previously cloned and characterized two human extracellular endoglucosamine 6-sulfatases, HSulf-1 and HSulf-2, which selectively liberate the 6-O sulfate groups on glucosamines present in N, 6-O, and 2-O trisulfated disaccharides of intact HS and heparins. These enzymes serve important roles in development and are upregulated in a number of cancers. To determine whether the Sulfs act on the trisulfated disaccharides that exist on the cell surface, we expressed HSulfs in cultured cells and performed a flow cytometric analysis with... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133179 Thu, 31 Dec 2009 09:10:06 +0100 3133179 http://www.medworm.com/index.php?rid=3133178&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F166%3Frss%3D1 N-Acetylglucosaminlyltransferase-V (GnT-V) synthesizes GlcNAcβ1,6Man branched N-glycans both in vitro and in vivo. A paralog, GnT-Vb (or GnT-IX), has also been shown to synthesize both GlcNAcβ1,6Man branched N- and O-glycans. GnT-V is expressed in most human and rodent tissues while GnT-Vb expression is limited mainly to neural tissue and testes. It is of interest, therefore, to compare the catalytic properties and reaction kinetics of these sister enzymes. The results demonstrate that while GnT-V was fully active without exogenous cation and in the presence of EDTA, the activity of GnT-Vb was stimulated over 4-fold in the presence of 10 mM Mn++. The pH optimum for GnT-V was in the range of 6.5–7.0, while that of GnT-Vb was 8.0. common for glycosyltransferases active in bra... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133178 Thu, 31 Dec 2009 09:10:06 +0100 3133178 http://www.medworm.com/index.php?rid=3133177&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F158%3Frss%3D1 We cloned, expressed, and characterized a novel β-galactoside 2,6-sialyltransferase from Photobacterium leiognathi strain JT-SHIZ-119. The protein showed 56–96% identity to the marine bacterial 2,6-sialyltransferases classified into glycosyltransferase family 80. The sialyltransferase activity of the N-terminal truncated form of the recombinant enzyme was 1477 U/L of Escherichia coli culture. The truncated recombinant enzyme was purified as a single band by sodium dodecyl sulfate polyacrylamide gel electrophoresis through 3 column chromatography steps. The enzyme had distinct activity compared with known marine bacterial 2,6-sialyltransferases. Although 2,6-sialyltransferases cloned from marine bacteria, such as Photobacterium damselae strain JT0160, P. leiognathi strain JT-SHIZ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133177 Thu, 31 Dec 2009 09:10:06 +0100 3133177 http://www.medworm.com/index.php?rid=3133176&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F148%3Frss%3D1 Sialidases are widely distributed glycohydrolytic enzymes removing sialic acid residues from glycoconjugates. In mammals, several sialidases with different subcellular localizations and biochemical features have been described. NEU4, the most recently identified member of the human sialidase family, is found in two forms, NEU4 long and NEU4 short, differing in the presence of a 12-amino-acid sequence at the N-terminus. Contradictory data are present in the literature about the subcellular distribution of these enzymes, their membrane anchoring mechanism being still unclear. In this work, we investigate the human NEU4 long and NEU4 short membrane anchoring mechanism and their subcellular localization. Protein extraction with Triton X-114 and sodium carbonate and cross-linking experiments de... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133176 Thu, 31 Dec 2009 09:10:06 +0100 3133176 http://www.medworm.com/index.php?rid=3133175&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F138%3Frss%3D1 In order to explore the structural basis for adaptability in near germline monoclonal antibodies (mAb), we have examined the specificity of the promiscuous mAb S67-27 to both naturally derived carbohydrate antigens and a variety of synthetic nonnatural antigens based on the bacterial lipopolysaccharide component 3-deoxy--d-manno-oct-2-ulosonic acid (Kdo). One such analog, a 7-O-methyl (7-O-Me) Kdo disaccharide, was found to bind to the antibody with at least 30-fold higher affinity than any other antigen tested. The structure of S67-27 in complex with this analog and three other naturally occurring Kdo antigens revealed that the enhanced affinity of the mAb for the synthetic analog was accomplished by the strategic positioning of CDR H3 away from a conserved Kdo binding pocket that allowed... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133175 Thu, 31 Dec 2009 09:10:06 +0100 3133175 http://www.medworm.com/index.php?rid=3133174&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2F137%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133174 Thu, 31 Dec 2009 09:10:06 +0100 3133174 http://www.medworm.com/index.php?rid=3133173&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133173 Thu, 31 Dec 2009 09:10:06 +0100 3133173 http://www.medworm.com/index.php?rid=3133172&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133172 Thu, 31 Dec 2009 09:10:06 +0100 3133172 http://www.medworm.com/index.php?rid=3133171&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F2%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3133171 Thu, 31 Dec 2009 09:10:06 +0100 3133171 http://www.medworm.com/index.php?rid=3026065&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F127%3Frss%3D1 A major surface constituent of Echinococcus multilocularis adult worms, referred to as an EmA9 antigen, was immunoaffinity purified and identified as a high-molecular-weight glycoconjugate. Labeling studies using the monoclonal antibody MAbEmA9 indicated that this antigen undergoes a regulated expression during the development from the larval to the adult parasite. Chemical modification of carbohydrate by periodate oxidation resulted in a reduced reactivity with antigen-specific antibodies. Non-reductive β-elimination of the purified molecule indicated the presence of O-linked glycans attached to threonine residues. Carbohydrate compositional analyses indicated the presence of N- and O-glycans with the ratio of carbohydrate to protein being 1.5:1 (w/w). N- and O-linked glycans were re... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026065 Wed, 25 Nov 2009 07:57:37 +0100 3026065 http://www.medworm.com/index.php?rid=3026064&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F118%3Frss%3D1 Monosialoganglioside fraction of YAC-1 lymphoma cells was comprehensively analyzed and structurally defined by nano-high-performance liquid chromatography (nanoHPLC) in on-line conjunction with electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF MS). An efficient separation and sensitive detection of Neu5Gc-containing gangliosides from Neu5Ac-containing analogues was for the first time accomplished in a single nanoHPLC/ESI-QTOF MS run, as demonstrated for mouse hybridoma cell GM3 fraction containing GM3(Neu5Ac) and GM3(Neu5Gc) species and further applied for the analysis of YAC-1 lymphoma cell monosialoganglioside fraction. New insights into YAC-1 monosialoganglioside mixture heterogeneity were obtained: 31 distinct species, comprising 18 Neu5Gc-containing ganglio... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026064 Wed, 25 Nov 2009 07:57:37 +0100 3026064 http://www.medworm.com/index.php?rid=3026063&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F107%3Frss%3D1 In this study, we analyzed wild-type and GNE-deficient embryonic stem cells from mice. We found for the first time that proliferation is directly correlated with GNE-expression and the cellular sialic acid concentration. Furthermore, we identified growth-related genes that are differentially expressed in GNE-deficient embryonic stem cells compared to wild-type embryonic stem cells. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026063 Wed, 25 Nov 2009 07:57:37 +0100 3026063 http://www.medworm.com/index.php?rid=3026062&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F99%3Frss%3D1 Alteration of glycoprotein glycans often changes various properties of the target glycoprotein and contributes to a wide variety of diseases. Here, we focused on the N-glycans of amyloid precursor protein whose cleaved fragment, β-amyloid, is thought to cause much of the pathology of Alzheimer's disease (AD). We previously determined the N-glycan structures of normal and mutant amyloid precursor proteins (the Swedish type and the London type). In comparison with normal amyloid precursor protein, mutant amyloid precursor proteins had higher contents of bisecting GlcNAc residues. Because N-acetylglucosaminyltransferase III (GnT-III) is the glycosyltransferase responsible for synthesizing a bisecting GlcNAc residue, the current report measured GnT-III mRNA expression levels in the brains... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026062 Wed, 25 Nov 2009 07:57:37 +0100 3026062 http://www.medworm.com/index.php?rid=3026061&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F87%3Frss%3D1 The opportunistic pathogen Burkholderia cenocepacia contains three soluble carbohydrate-binding proteins, related to the fucose-binding lectin PA-IIL from Pseudomonas aeruginosa. All contain a PA-IIL-like domain and two of them have an additional N-terminal domain that displays no sequence similarities with known proteins. Printed arrays screening performed on the shortest one, B. cenocepacia lectin A (BC2L-A), demonstrated the strict specificity for oligomannose-type N-glycan structures (Lameignere E, Malinovská L, Sláviková M, Duchaud E, Mitchell EP, Varrot A, Sedo O, Imberty A, Wimmerová M. 2008. Structural basis for mannose recognition by a lectin from opportunistic bacteria Burkholderia cenocepacia. Biochem J. 411:307–318.). The disaccharides Man1-2Ma... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026061 Wed, 25 Nov 2009 07:57:37 +0100 3026061 http://www.medworm.com/index.php?rid=3026060&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F78%3Frss%3D1 In this study, we focused on GD3, a b-series ganglioside that is enriched in the immature brain and the subventricular zone (SVZ) of the postnatal and adult brain, and evaluated the usefulness of GD3 as a cell-surface biomarker for identifying NSCs. We demonstrated that GD3 was expressed in more than 80% of NSCs prepared from embryonic, postnatal, and adult mouse brain tissue by the neurosphere culture method. The percentage of GD3-expressing NSCs in neurospheres was nearly the same as it was in neurospheres derived from embryonic, postnatal, and adult brains but decreased drastically to about 40% after differentiation. GD3+ cells isolated from embryonic mouse striata, postnatal, and adult mouse SVZs by fluorescence-activated cell sorting with an R24 anti-GD3 monoclonal antibody efficientl... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026060 Wed, 25 Nov 2009 07:57:37 +0100 3026060 http://www.medworm.com/index.php?rid=3026059&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F62%3Frss%3D1 In this paper, we describe the effects of the expression of GM3 synthase at high levels in human ovarian carcinoma cells. Overexpression of GM3 synthase in A2780 cells consistently resulted in elevated ganglioside (GM3, GM2 and GD1a) levels. GM3 synthase overexpressing cells had a growth rate similar to wild-type cells, but showed a strongly reduced in vitro cell motility accompanied by reduced levels of the epithelial-mesenchymal transition marker smooth muscle actin. A similar reduction in cell motility was observed upon treatment with exogenous GM3, GM2, and GM1, but not with GD1a. A photolabeling experiment using radioactive and photoactivable GM3 highlighted several proteins directly interacting with GM3. Among those, caveolin-1 was identified as a GM3-interacting protein in GM3 synth... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026059 Wed, 25 Nov 2009 07:57:37 +0100 3026059 http://www.medworm.com/index.php?rid=3026058&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F55%3Frss%3D1 Glucose residues from N-linked oligosaccharides are removed by glucosidases I and II in the endoplasmic reticulum (ER) or by the alternate endomannosidase pathway in the Golgi apparatus. Our morphological analysis demonstrates that recombinant rat endomannosidase exhibited a cis- and medial-Golgi localization alike the endogenous enzyme and its ER to Golgi transport is COP II mediated. Recombinant endomannosidase undergoes a posttranslational modification, which is not related to N-or O-glycosylation. A shift in molecular mass of recombinant endomannosidase was observed upon phosphatase digestion but not for ER-retained CHO cell endomannosidase. Furthermore, immunoprecipitation of 35S- and 33P-labeled endomannosidase expressed in CHO-K1 cells suggests that recombinant endomannosidase under... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026058 Wed, 25 Nov 2009 07:57:37 +0100 3026058 http://www.medworm.com/index.php?rid=3026057&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F41%3Frss%3D1 LT-IIb, a type II heat-labile enterotoxin of Escherichia coli, is a potent immunologic adjuvant with high affinity binding for ganglioside GD1a. Earlier study suggested that LT-IIb bound preferentially to the terminal sugar sequence NeuAc2-3Galβ1-3GalNAc. However, studies in our laboratory suggested a less restrictive binding epitope. LT-IIb(T13I), an LT-IIb variant, engineered by a single isoleucine-threonine substitution, retains biological activity, but with less robust inflammatory effects. We theorized that LT-IIb has a less restrictive binding epitope than previously proposed and that immunologic differences between LT-IIb and LT-IIb (T13I) correlate with subtle ganglioside binding differences. Ganglioside binding epitopes, determined by affinity overlay immunoblotting and enzym... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026057 Wed, 25 Nov 2009 07:57:37 +0100 3026057 http://www.medworm.com/index.php?rid=3026056&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F33%3Frss%3D1 In this study, we report the effects of hypoxia on PG secreted by human monocyte-derived macrophages (HMDM) and the potential regulation by the transcription factor hypoxia-inducible factor (HIF-1 and HIF-2). We found that versican co-localized with HIF-1 in macrophage-rich areas in human advanced atherosclerotic lesions. Versican and perlecan mRNA expression increased after exposure to 0.5% O2 (hypoxia) compared with 21% O2 (control cells). Using precursors to GAG biosynthesis combined with immunoabsorption with a versican antibody an increased versican synthesis was detected at hypoxia. Furthermore, siRNA knockdown of HIF-1 and HIF-2 in THP-1 cells showed that the hypoxic induction of versican and perlecan mRNA expression involved HIF signaling. Versican expression was co-regulated by HI... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026056 Wed, 25 Nov 2009 07:57:37 +0100 3026056 http://www.medworm.com/index.php?rid=3026055&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F24%3Frss%3D1 Gaucher disease, the most common lysosomal storage disease, can be treated with enzyme replacement therapy (ERT), in which defective acid-β-glucosidase (GlcCerase) is supplemented by a recombinant, active enzyme. The X-ray structures of recombinant GlcCerase produced in Chinese hamster ovary cells (imiglucerase, Cerezyme®) and in transgenic carrot cells (prGCD) have been previously solved. We now describe the structure and characteristics of a novel form of GlcCerase under investigation for the treatment of Gaucher disease, Gene-ActivatedTM human GlcCerase (velaglucerase alfa). In contrast to imiglucerase and prGCD, velaglucerase alfa contains the native human enzyme sequence. All three GlcCerases consist of three domains, with the active site located in domain III. The distances ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026055 Wed, 25 Nov 2009 07:57:37 +0100 3026055 http://www.medworm.com/index.php?rid=3026054&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F13%3Frss%3D1 In this study, GLYCOv2 glycogene microarray technology was used for the first time to identify the differentially expressed glycosylation-related genes in healing mouse corneas. Of ~2000 glycogenes on the array, the expression of 11 glycosytransferase and glycosidase enzymes was upregulated and that of 19 was downregulated more than 1.5-fold in healing corneas compared with the normal, uninjured corneas. Among them, notably, glycosyltransferases, β3GalT5, T-synthase, and GnTIVb, were all found to be induced in the corneas in response to injury, whereas, GnTIII and many sialyltransferases were downregulated. Interestingly, it appears that the glycan structures on glycoproteins and glycolipids, expressed in healing corneas as a result of differential regulation of these glycosyltransfer... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026054 Wed, 25 Nov 2009 07:57:37 +0100 3026054 http://www.medworm.com/index.php?rid=3026053&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F2%3Frss%3D1 Parasitic helminths (worms) co-evolved with vertebrate immune systems to enable long-term survival of worms in infected hosts. Among their survival strategies, worms use their glycans within glycoproteins and glycolipids, which are abundant on helminth surfaces and in their excretory/ secretory products, to regulate and suppress host immune responses. Many helminths express unusual and antigenic (nonhost-like) glycans, including those containing polyfucose, tyvelose, terminal GalNAc, phosphorylcholine, methyl groups, and sugars in unusual linkages. In addition, some glycan antigens are expressed that share structural features with those in their intermediate and vertebrate hosts (host-like glycans), including LeX (Galβ1-4[Fuc1-3]GlcNAc-), LDNF (GalNAcβ1-4[Fuc1-3]GlcNAc-), LDN (Ga... Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026053 Wed, 25 Nov 2009 07:57:37 +0100 3026053 http://www.medworm.com/index.php?rid=3026052&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2F1%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026052 Wed, 25 Nov 2009 07:57:37 +0100 3026052 http://www.medworm.com/index.php?rid=3026051&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026051 Wed, 25 Nov 2009 07:57:37 +0100 3026051 http://www.medworm.com/index.php?rid=3026050&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026050 Wed, 25 Nov 2009 07:57:37 +0100 3026050 http://www.medworm.com/index.php?rid=3026049&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F20%2F1%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=3026049 Wed, 25 Nov 2009 07:57:37 +0100 3026049 http://www.medworm.com/index.php?rid=2943034&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1570%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943034 Thu, 29 Oct 2009 15:38:44 +0100 2943034 http://www.medworm.com/index.php?rid=2943033&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1568%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943033 Thu, 29 Oct 2009 15:38:44 +0100 2943033 http://www.medworm.com/index.php?rid=2943032&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1563%3Frss%3D1 Despite ongoing harmonization efforts, the major carbohydrate sequence databases following the first initiative in this field, CarbBank, are still isolated islands, with mechanisms for automatic structure exchange and comparison largely missing. This unfavorable situation has been overcome with a systematic data integration effort, resulting in the GlycomeDB, a meta-database for public carbohydrate sequences. It contains at present 35,056 unique structures in GlycoCT encoding, referencing more than 100,000 external records from 1845 different taxonomic sources. We have created a user-friendly, web-based graphical interface which allows taxonomic and structural data to be entered and searched for. The structural search possibilities include substructure search, similarity search, and maximu... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943032 Thu, 29 Oct 2009 15:38:44 +0100 2943032 http://www.medworm.com/index.php?rid=2943031&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1554%3Frss%3D1 Inefficient glycosylation caused by defective synthesis of lipid-linked oligosaccharide donor results in multi-systemic syndromes known as congenital disorders of glycosylation type I (CDG-I). Strong loss of function mutations are embryonic lethal, patients with partial losses of function are occasionally born but are very ill, presenting with defects in virtually every tissue. CDG-I clinical expression varies considerably and ranges from very mild to severe, and the underlying cause of the variable clinical features is not yet understood. We postulate that accompanying defects in an individual's genetic background enhance the severity of CDG-I clinical phenotypes. Since so many protein structures and functions are compromised in CDG-I illnesses, the gene products that are dependent on N-l... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943031 Thu, 29 Oct 2009 15:38:44 +0100 2943031 http://www.medworm.com/index.php?rid=2943030&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1547%3Frss%3D1 Glycan heterogeneity was shown to be associated with numerous diseases and glycan analysis has a great diagnostic potential. Recently, we reported high biological variability of human plasma N-glycome at the level of population. The observed variations were larger than changes reported to be associated with some diseases; thus, it was of great importance to examine the temporal constancy of human N-glycome before glycosylation changes could be routinely analyzed in diagnostic laboratories. Plasma samples were taken from 12 healthy individuals. The blood was drawn on seven occasions during 5 days. N-Linked glycans, released from plasma proteins, were separated using hydrophilic interaction high-performance liquid chromatography into 16 groups (GP1-GP16) and quantified. The results showed ve... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943030 Thu, 29 Oct 2009 15:38:44 +0100 2943030 http://www.medworm.com/index.php?rid=2943029&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1537%3Frss%3D1 The interactions of glycosaminoglycans (GAGs) with proteins underlie a wide range of important biological processes. However, the study of such binding reactions has been hampered by the lack of a simple frontline analysis technique. Previously, we have reported that cold plasma polymerization can be used to coat microtiter plate surfaces with allyl amine to which GAGs (e.g., heparin) can be noncovalently immobilized retaining their ability to interact with proteins. Here, we have assessed the capabilities of surface coats derived from different ratios of allyl amine and octadiene (100:0 to 0:100) to support the binding of diverse GAGs (e.g., chondroitin-4-sulfate, dermatan sulfate, heparin preparations, and hyaluronan) in a functionally active state. The Link module from TSG-6 was used as... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943029 Thu, 29 Oct 2009 15:38:44 +0100 2943029 http://www.medworm.com/index.php?rid=2943028&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1525%3Frss%3D1 In this study, we have used an animal model of nonsecretors, Fut2-null mice, to characterize the glycosylation profile and evaluate the effect of the observed glycan expression modifications in the process of H. pylori adhesion. We have demonstrated expression of terminal difucosylated glycan structures in C57Bl/6 mice gastric mucosa and that Fut2-null mice showed marked alteration in gastric mucosa glycosylation, characterized by diminished expression of (1,2)fucosylated structures as indicated by lectin and antibody staining and further confirmed by mass spectrometry analysis. This altered glycosylation profile was further confirmed by the absence of Fuc(1,2)-dependent binding of calicivirus virus-like particles. Finally, using a panel of H. pylori strains, with different adhesin express... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943028 Thu, 29 Oct 2009 15:38:44 +0100 2943028 http://www.medworm.com/index.php?rid=2943027&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1511%3Frss%3D1 We have recently reported that the CXC-chemokine stromal cell-derived factor-1 (SDF-1)/CXCL12 induces proliferation, migration, and invasion of the Huh7 human hepatoma cells through its G-protein-coupled receptor CXCR4 and that glycosaminoglycans (GAGs) are involved in these events. Here, we demonstrate by surface plasmon resonance that the chemokine binds to GAG mimetics obtained by grafting carboxylate, sulfate or acetate groups onto a dextran backbone. We also demonstrate that chemically modified dextrans inhibit SDF-1/CXCL12-mediated in vitro chemotaxis and anchorage-independent cell growth in a dose-dependent manner. The binding of GAG mimetics to the chemokine and their effects in modulating the SDF-1/CXCL12 biological activities are mainly related to the presence of sulfate groups. ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943027 Thu, 29 Oct 2009 15:38:44 +0100 2943027 http://www.medworm.com/index.php?rid=2943026&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1503%3Frss%3D1 Galβ1-4GlcNAc is thought to be a common disaccharide unit preferentially recognized by vertebrate galectins. Eight-amino-acid residues conserved in proteins belonging to the galectin family have been suggested to be responsible for recognition. Meanwhile, we isolated and analyzed endogenous N-glycans of Caenorhabditis elegans that were captured by a C. elegans galectin LEC-6 and demonstrated that the unit of recognition for LEC-6 is a Gal-Fuc disaccharide, though the linkage between these residues was not confirmed. In the present study, we chemically synthesized Galβ1-4Fuc and Galβ1-3Fuc labeled with 2-aminopyridine (PA) and demonstrated that LEC-6 interacts with PA-Galβ1-4Fuc more strongly than PA-Galβ1-3Fuc by frontal affinity chromatography (FAC). Galβ1-4F... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943026 Thu, 29 Oct 2009 15:38:44 +0100 2943026 http://www.medworm.com/index.php?rid=2943025&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1492%3Frss%3D1 Old age is linked to numerous changes of body functions such as salivation, gastrointestinal motility, and permeability all linked to central and enteric nervous system decline. Thus, gut motility and barrier functions suffer. Sialic acid plays a key role in the nervous system at large and for many receptor functions specifically. Decreased sialylation in the elderly suggests an endogenous sialic acid deficit. We used a rat model of aging, to ask whether sialic acid feeding would affect (i) stimulated salivation, (ii) gut functions, and (iii) sialic acid levels and neuronal markers in brain and gut. We observed reduced levels of pilocarpine-stimulated salivation in old versus young rats and restored this function by sialic acid feeding. Brain ganglioside bound sialic acid levels were found... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943025 Thu, 29 Oct 2009 15:38:44 +0100 2943025 http://www.medworm.com/index.php?rid=2943024&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1485%3Frss%3D1 Chondroitin sulfate (CS), a constituent of proteoglycans, is a key component of the connective tissues and it is widely used as a precautionary drug for joint diseases; for this reason, the increased demand of this polysaccharide has posed the problem to identify new and secure sources of this product. In this context, CS from the cartilage of the lesser spotted dogfish (Scyliorhinus canicula, a cartilaginous fish) was isolated and investigated through chemical and spectroscopical techniques. The structural elucidation was performed on the entire polysaccharide and confirmed analyzing the products obtained via ABC lyase treatment. As a result, its compositional analysis disclosed the occurrence of CS-A, CS-C, CS-D, and CS-0S motifs in the ratio of 41, 32, 19.8, and 8.2%, respectively. Addi... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943024 Thu, 29 Oct 2009 15:38:44 +0100 2943024 http://www.medworm.com/index.php?rid=2943023&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1473%3Frss%3D1 Surfactant protein D (SP-D), a lectin that recognizes carbohydrates via its C-type carbohydrate recognition domains (CRDs), regulates Mycobacterium tuberculosis (M.tb)–macrophage interactions via recognition of M.tb mannosylated cell wall components. SP-D binds to, agglutinates, and reduces phagocytosis and intracellular growth of M.tb. Species-specific variations in the CRD amino acid sequence contribute to carbohydrate recognition preferences and have been exploited to enhance the antimicrobial properties of SP-D in vitro. Here, we characterized the binding interaction between several wild-type and mutant SP-D neck + CRD trimeric subunits (NCRDs) and pathogenic and nonpathogenic mycobacterial species. Specific amino acid substitutions (i.e., the 343-amino-acid position) that flank ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943023 Thu, 29 Oct 2009 15:38:43 +0100 2943023 http://www.medworm.com/index.php?rid=2943022&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1462%3Frss%3D1 Trypanosoma cruzi relies on highly galactosylated molecules as virulence factors and the enzymes involved in sugar biosynthesis are potential therapeutic targets. The synthesis of UDP-galactose in T. cruzi requires the activity of phosphoglucomutase (PGM), the enzyme that catalyzes the interconversion of glucose-6-phosphate and glucose-1-phosphate. Several enzymes that participate in carbohydrate metabolism in trypanosomes are confined to specialized peroxisome-like organelles called glycosomes. The majority of glycosomal proteins contain peroxisome-targeting signals (PTS) at the COOH- or at the amino-terminus, which drive their transport to glycosomes. We had previously identified the T. cruzi PGM gene (TcPGM) and demonstrated that it encodes a functional enzyme. Here, we show that, in co... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943022 Thu, 29 Oct 2009 15:38:43 +0100 2943022 http://www.medworm.com/index.php?rid=2943021&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1452%3Frss%3D1 Chitinase-A (CrChi-A) was purified from leaf rachises of Cycas revoluta by several steps of column chromatography. It was found to be a glycoprotein with a molecular mass of 40 kDa and an isoelectric point of 5.6. CrChi-A produced mainly (GlcNAc)3 from the substrate (GlcNAc)6 through a retaining mechanism. More interestingly, CrChi-A exhibited transglycosylation activity, which has not been observed in plant chitinases investigated so far. A cDNA encoding CrChi-A was cloned by rapid amplification of cDNA ends and polymerase chain reaction procedures. It consisted of 1399 nucleotides and encoded an open reading frame of 387-amino-acid residues. Sequence analysis indicated that CrChi-A belongs to the group of plant class V chitinases. From peptide mapping and mass spectrometry of the na... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943021 Thu, 29 Oct 2009 15:38:43 +0100 2943021 http://www.medworm.com/index.php?rid=2943020&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1446%3Frss%3D1 This study also suggests the biological relevance of the glycosphingolipid as a dietary source of hydra which possesses EGCase as a digestion enzyme. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943020 Thu, 29 Oct 2009 15:38:43 +0100 2943020 http://www.medworm.com/index.php?rid=2943019&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1436%3Frss%3D1 In this study, we have used standard NMR techniques to unequivocally show that the PEtn residue is actually located at the 6-position and not at the 7-position of the HepII residue in all of these strains. The 6-PEtn transferase genes were sequenced and their translated amino acid sequences were shown to be greater than 96% identical to that of the Lpt6 transferase from the L4 immunotype strain, which has been shown to transfer PEtn to the 6-position of the distal heptose residue. We discuss the implications of these findings with respect to the immunotyping scheme for the meningococci and in the context of LPS-based vaccine development. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943019 Thu, 29 Oct 2009 15:38:43 +0100 2943019 http://www.medworm.com/index.php?rid=2943018&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1427%3Frss%3D1 In this report, we report differences in the cancer-specific sialic acid content of gp96 purified from normal rat prostate compared to two rat prostate cancers, MAT-LyLu and Dunning G, as well as between two human prostate cancer cells, LnCaP and DU145. We also examined the modulatory effect of sialic acid residues on the binding of gp96 to APCs and its subsequent activation. Our results supported the contention that significant differences in the sialic acid content exist between Dunning G, MAT-LyLu, and normal rat prostate gp96, which affected its binding and biochemical activity to APCs. We therefore postulate that varied glycans of HPS96, a hitherto neglected structural component, may play a pivotal role in its anticancer activity. We suggest that construction of the glycan tree is a k... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943018 Thu, 29 Oct 2009 15:38:43 +0100 2943018 http://www.medworm.com/index.php?rid=2943017&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1417%3Frss%3D1 A simple and inexpensive method was developed to rapidly define the specificity of mannose-specific lectins toward oligomannoside-type structures. The method involved the interaction of a mixture of N-[14C]-acetylated glycoasparagines, prepared by exhaustive pronase digestion of bovine pancreatic ribonuclease B and N-[14C]-acetylation with [14C]-acetic anhydride and containing all the possible oligomannoside-type N-glycans, with the lectin immobilized on Sepharose-4B. After exhaustive desalting, the obtained fractions were separated by high-performance thin-layer chromatography on silica gel plates and visualized by autoradiography with intensifying screen. As an example of the usefulness of this method, the fine specificity of artocarpin, the mannose-specificity lectin isolated from seeds... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943017 Thu, 29 Oct 2009 15:38:43 +0100 2943017 http://www.medworm.com/index.php?rid=2943016&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1408%3Frss%3D1 Glucosidase II (GluII) is a glycan-trimming enzyme active on nascent glycoproteins in the endoplasmic reticulum (ER). It trims the middle and innermost glucose residues (Glc2 and Glc1) from N-linked glycans. The monoglucosylated glycan produced by the first GluII trimming reaction is recognized by calnexin/calreticulin and serves as the signal for entry into this folding pathway. GluII is a heterodimer of and β subunits corresponding to yeast Gls2p and Gtb1p, respectively. While Gls2p contains the glucosyl hydrolase active site, the Gtb1p subunit has previously been shown to be essential for the Glc1 trimming event. Here we demonstrate that Gtb1p also determines the rate of Glc2 trimming. In order to further dissect these activities we mutagenized a number of conserved residues across... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943016 Thu, 29 Oct 2009 15:38:43 +0100 2943016 http://www.medworm.com/index.php?rid=2943015&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1402%3Frss%3D1 Galectin-1, the prototype of a family of β-galactoside-binding proteins, has been implicated in a wide variety of biological processes. Data presented herein show that galectin-1 stimulates monocyte migration in a dose-dependent manner but is not chemotactic for macrophages. Galectin-1-induced monocyte chemotaxis is blocked by lactose and inhibited by an anti-galectin-1 antibody but not by nonspecific antibodies. Furthermore, galectin-1-mediated monocyte migration was significantly inhibited by MEK inhibitors in a rapid, time-dependent manner suggesting that MAP kinase pathways are involved in galectin-1. Migration was also almost completely blocked by pertussis toxin implying G-protein involvement in the galectin-1-induced chemotaxis. These results demonstrate a role for galectin-1 i... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943015 Thu, 29 Oct 2009 15:38:43 +0100 2943015 http://www.medworm.com/index.php?rid=2943014&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1382%3Frss%3D1 This report provides a perspective on metabolic glycoengineering methodology developed over the past two decades that allows natural sialic acids to be replaced with chemical variants in living cells and animals. Examples are given demonstrating how this technology provides the glycoscientist with chemical tools that are beginning to reproduce Mother Nature's control over complex biological systems – such as the human brain – through subtle modifications in sialic acid chemistry. Several metabolic substrates (e.g., ManNAc, Neu5Ac, and CMP-Neu5Ac analogs) can be used to feed flux into the sialic acid biosynthetic pathway resulting in numerous – and sometime quite unexpected – biological repercussions upon nonnatural sialoside display in cellular glycans. Once on... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943014 Thu, 29 Oct 2009 15:38:43 +0100 2943014 http://www.medworm.com/index.php?rid=2943013&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2F1381%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943013 Thu, 29 Oct 2009 15:38:43 +0100 2943013 http://www.medworm.com/index.php?rid=2943012&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2Fiv%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943012 Thu, 29 Oct 2009 15:38:43 +0100 2943012 http://www.medworm.com/index.php?rid=2943011&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943011 Thu, 29 Oct 2009 15:38:43 +0100 2943011 http://www.medworm.com/index.php?rid=2943010&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F12%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2943010 Thu, 29 Oct 2009 15:38:43 +0100 2943010 http://www.medworm.com/index.php?rid=2865121&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1259%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865121 Tue, 06 Oct 2009 04:39:41 +0100 2865121 http://www.medworm.com/index.php?rid=2865120&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1248%3Frss%3D1 Extracellular galectin-3 participates in the control of B2 lymphocyte migration and adhesion and of their differentiation into plasma cells. Here, we analyzed the role of galectin-3 in B1-cell physiology and the balance between B1a and B1b lymphocytes in the peritoneal cavity. In galectin-3–/– mice, the total number of B1a lymphocytes was lower, while B1b lymphocyte number was higher as compared to wild-type mice. The differentiation of B1a cells into plasma cells was associated with their abnormal adhesion and location on the mesentery. The B220 and CD43, constitutively expressed by B1 lymphocytes, were respectively up- and downregulated in galectin-3–/– mice. Mononuclear cells were strongly adhered to the mesenteric membranes of both CD43–/– and galect... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865120 Tue, 06 Oct 2009 04:39:41 +0100 2865120 http://www.medworm.com/index.php?rid=2865119&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1235%3Frss%3D1 Arabinogalactan (AG) and lipoarabinomannan (LAM) are the two major cell wall (lipo)polysaccharides of mycobacteria. They share arabinan chains made of linear segments of -1,5-linked d-Araf residues with some -1,3-branching, the biosynthesis of which offers opportunities for new chemotherapeutics. In search of the missing arabinofuranosyltransferases (AraTs) responsible for the formation of the arabinan domains of AG and LAM in Mycobacterium tuberculosis, we identified Rv0236c (AftD) as a putative membrane-associated polyprenyl-dependent glycosyltransferase. AftD is 1400 amino acid-long, making it the largest predicted glycosyltransferase of its class in the M. tuberculosis genome. Assays using cell-free extracts from recombinant Mycobacterium smegmatis and Corynebacterium glutamicum strain... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865119 Tue, 06 Oct 2009 04:39:41 +0100 2865119 http://www.medworm.com/index.php?rid=2865118&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1224%3Frss%3D1 The first comparative thermodynamic study of the human blood group glycosyltransferases, -(1->3)-N-acetylgalactosaminyltransferase (GTA) and -(1->3)-galactosyltransferase (GTB), interacting with donor substrates, donor and acceptor analogs, and trisaccharide products in vitro is reported. The binding constants, measured at 24°C with the direct electrospray ionization mass spectrometry (ES-MS) assay, provide new insights into these model GTs and their interactions with substrate and product. Notably, the recombinant forms of GTA and GTB used in this study are shown to exist as homodimers, stabilized by noncovalent interactions at neutral pH. In the absence of divalent metal ion, neither GTA nor GTB exhibits any appreciable affinity for its native donors (UDP-GalNAc, UDP-Gal). Upon... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865118 Tue, 06 Oct 2009 04:39:41 +0100 2865118 http://www.medworm.com/index.php?rid=2865117&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1214%3Frss%3D1 This is the first structural elucidation of the lipooligosaccharide (LOS) endotoxin isolated from Burkholderia vietnamiensis, a clinically important member of Burkholderia cepacia complex, a group of over 10 opportunistic species that are highly problematic in cystic fibrosis. We have characterized a novel LOS structure extracted from two clonal strains of B. vietnamiensis isolated from a cystic fibrosis patient who underwent lung transplantation. Strains were selected from the pretransplantation and post-transplantation periods and endotoxin was extracted. Subsequent analysis interestingly revealed identical oligosaccharidic sequences, but variation in lipid A moieties. Further, both LOS fractions were tested for their immunostimulatory activity on human myelomonocytic U937 cells and for ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865117 Tue, 06 Oct 2009 04:39:41 +0100 2865117 http://www.medworm.com/index.php?rid=2865116&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1204%3Frss%3D1 Group B Streptococcus (GBS) is an important human pathogen and a model system for studying the roles of bacterial glycosylation in host–microbe interactions. Sialic acid (Sia), expressed prominently in the GBS capsular polysaccharide (CPS), mimics mammalian cell surface Sia and can interact with host Sia-binding proteins to subvert immune clearance mechanisms. Our earlier work has shown that GBS partially O-acetylates CPS Sia residues and employs an intracellular O-acetylation/de-O-acetylation cycle to control the final level of this surface Sia modification. Here, we examine the effects of point mutations in the NeuD O-acetyltransferase and NeuA O-acetylesterase on specific glycosylation phenotypes of GBS, pinpointing an isogenic strain pair that differs dramatically in the degree o... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865116 Tue, 06 Oct 2009 04:39:41 +0100 2865116 http://www.medworm.com/index.php?rid=2865115&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1197%3Frss%3D1 In conclusion, D4ST-1 is a key enzyme and is indispensable in the formation of important functional domains in dermatan sulfate and cannot be compensated by other 4-O-sulfotransferases. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865115 Tue, 06 Oct 2009 04:39:41 +0100 2865115 http://www.medworm.com/index.php?rid=2865114&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1185%3Frss%3D1 The solution conformation of a fully sulfated heparin-derived tetrasaccharide, I, was studied in the presence of a 4-fold excess of Ca2+. Proton–proton and proton–carbon residual dipolar couplings (RDCs) were measured in a neutral aligning medium. The order parameters of two rigid hexosamine rings of I were determined separately using singular value decomposition and ab initio structures of disaccharide fragments of I. The order parameters were very similar implying that a common order tensor can be used to analyze the structure of I. Using one order tensor, RDCs of both hexosamine rings were used as restraints in molecular dynamics simulations. RDCs of the inner iduronic acid were calculated for every point of the molecular dynamics trajectory. The fitting of the calculated RD... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865114 Tue, 06 Oct 2009 04:39:40 +0100 2865114 http://www.medworm.com/index.php?rid=2865113&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1176%3Frss%3D1 Susceptibility to norovirus infection has been linked to secretor status. Norovirus virus-like particles (VLPs; 0– 20 µg/mL) from the Norwalk (GI.1) and Dijon (GII.4) strains were assayed for binding to H type 1 and Lewis a pentaglycosylceramides, incorporated in laterally fluid supported lipid bilayers. Binding kinetics was monitored in real time in 40 µL stationary reaction chambers, using quartz crystal microbalance with dissipation (QCM-D) monitoring. Both strains displayed binding only to H type 1 and not to Lewis a glycosphingolipids, typical for epithelial cells of susceptible and resistant individuals, respectively. This binding specificity was confirmed by VLPs binding to the two glycosphingolipids chromatographed on TLC-plates. Experiments using bilayers with mi... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865113 Tue, 06 Oct 2009 04:39:40 +0100 2865113 http://www.medworm.com/index.php?rid=2865112&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1163%3Frss%3D1 Effective representation and characterization of biosynthetic pathways of glycosylation can be facilitated by mathematical modeling. This paper describes the expansion of a previously developed detailed model for N-linked glycosylation with the further application of the model to analyze MALDI-TOF mass spectra of human N-glycans in terms of underlying cellular enzyme activities. The glycosylation reaction network is automatically generated by the model, based on the reaction specificities of the glycosylation enzymes. The use of a molecular mass cutoff and a network pruning method typically limits the model size to about 10,000 glycan structures. This allows prediction of the complete glycan profile and its abundances for any set of assumed enzyme concentrations and reaction rate parameter... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865112 Tue, 06 Oct 2009 04:39:40 +0100 2865112 http://www.medworm.com/index.php?rid=2865111&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1155%3Frss%3D1 Screening of glycan arrays represents a powerful, high-throughput approach to defining oligosaccharide ligands for glycan-binding receptors, commonly referred to as lectins. Correlating results from such arrays with structural analysis of receptor–ligand complexes provide one way to validate the arrays. Using examples drawn from the family of proteins that contain C-type carbohydrate-recognition domains, this review illustrates how information from the arrays reflects the way that selectivity and affinity for glycan ligands is achieved. A range of binding profiles is observed, from very restricted binding to a small set of structurally similar ligands to binding of broad classes of ligands with related terminal sugars and even to failure to bind any of the glycans on an array. These ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865111 Tue, 06 Oct 2009 04:39:40 +0100 2865111 http://www.medworm.com/index.php?rid=2865110&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1152%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865110 Tue, 06 Oct 2009 04:39:40 +0100 2865110 http://www.medworm.com/index.php?rid=2865109&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2F1151%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865109 Tue, 06 Oct 2009 04:39:40 +0100 2865109 http://www.medworm.com/index.php?rid=2865108&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865108 Tue, 06 Oct 2009 04:39:40 +0100 2865108 http://www.medworm.com/index.php?rid=2865107&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865107 Tue, 06 Oct 2009 04:39:40 +0100 2865107 http://www.medworm.com/index.php?rid=2865106&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F11%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2865106 Tue, 06 Oct 2009 04:39:40 +0100 2865106 http://www.medworm.com/index.php?rid=2757057&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1136%3Frss%3D1 In this report, we demonstrate that the sulfated glycans, with and without additional sialylation, can be successfully permethylated by the sodium hydroxide slurry method and be distinguished from phosphorylated glycans by virtue of this derivatization. In conjunction with simple microscale postderivatization fractionation steps, permethyl derivatives fully retaining the negatively charged sulfate moiety and separated from the nonsulfated ones, can be efficiently detected and sequenced de novo by advanced MS/MS in the positive-ion mode. In particular, we show that the highly sequence and linkage informative high energy collision induced dissociation (CID) MS/MS afforded by MALDI-TOF/TOF can be extended to sulfoglycomic applications. The sulfated parent ion selected for CID MS/MS was found ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757057 Mon, 31 Aug 2009 23:00:00 +0100 2757057 http://www.medworm.com/index.php?rid=2757056&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1127%3Frss%3D1 Glucosidase II (GII) is a glycan-processing enzyme that trims two 1,3-linked glucose residues from N-glycan on newly synthesized glycoproteins. Trimming of the first 1,3-linked glucose from Glc2Man9GlcNAc2 (G2M9) is important for a glycoprotein to interact with calnexin/calreticulin (CNX/CRT), and cleavage of the innermost glucose from Glc1Man9GlcNAc2 (G1M9) sets glycoproteins free from the CNX/CRT cycle and allows them to proceed to the Golgi apparatus. GII is a heterodimeric complex consisting of a catalytic subunit (GII) and a tightly associated β subunit (GIIβ) that contains a mannose 6-phosphate receptor homology (MRH) domain. A recent study has suggested a possible involvement of the MRH domain of GIIβ (GIIβ-MRH) in the glucose trimming process via its putative su... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757056 Mon, 31 Aug 2009 23:00:00 +0100 2757056 http://www.medworm.com/index.php?rid=2757055&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1116%3Frss%3D1 Surface plasmon resonance (SPR) has been used to assay the roles of amino acid residues in the substrate binding cleft of Trichoderma harzianum chitinase Chit42, which belongs to the glycoside hydrolase family 18 (GH-18). Nine different Chit42 variants having amino acid mutations along the binding site cleft at subsites –4 to +2 were created and characterized with regard to their affinity toward chitinous and non-chitinous oligosaccharides. The catalytically inactive Chit42 mutant E172Q was used as the template for making the additional mutations. The E172Q mutant bound chitinoligosaccharides (tetra-, penta- and hexamer) with an increasing affinity from 12 to 0.2 µM whereas no binding of chitinbiose, -triose or 3'-sialyl-N-acetyllactosamine (Neu5Ac-3Galβ-4GlcNAc) could be ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757055 Mon, 31 Aug 2009 23:00:00 +0100 2757055 http://www.medworm.com/index.php?rid=2757054&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1103%3Frss%3D1 We report the first use of molecular dynamics (MD) free energy calculations using the MM/PBSA method to investigate the binding of GAGs to protein molecules, namely the platelet endothelial cell adhesion molecule 1 (PECAM-1) and annexin A2. Calculations of the free energy of the binding of heparin fragments of different sizes reveal the existence of a region of low GAG-binding affinity in domains 5–6 of PECAM-1 and a region of high affinity in domains 2–3, consistent with experimental data and ligand–protein docking studies. A conformational hinge movement between domains 2 and 3 was observed, which allows the binding of heparin fragments of increasing size (pentasaccharides to octasaccharides) with an increasingly higher binding affinity. Similar simulations of the bindi... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757054 Mon, 31 Aug 2009 23:00:00 +0100 2757054 http://www.medworm.com/index.php?rid=2757053&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1094%3Frss%3D1 A prominent feature of the rodent Muc3 SEA module is the precursor cleavage event that segregates the O-glycosylated N-terminal fragment and transmembrane domain into the noncovalently attached heterodimer. There are seven potential N-glycosylation sites that occur in a cluster in the SEA module of Muc3. However, it is unknown if these sites are modified or what the function of these N-glycans may be in the SEA module. Our data show that the proteolytic cleavage of the rodent Muc3 SEA module was partially prevented by treatment with tunicamycin, an inhibitor of N-glycosylation. Each single mutant of the seven N-glycosylation sites (N1A, N2A, N3A, N4A, N5A, N6A, and N7A) and multiple mutants, including double (N34A) and triple (N345A) mutants, and mutants with four (N3457A), five (N34567A),... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757053 Mon, 31 Aug 2009 23:00:00 +0100 2757053 http://www.medworm.com/index.php?rid=2757052&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1082%3Frss%3D1 We have cloned a cDNA sequence encoding the second bovine β-galactoside-2,6-sialyltransferase whose sequence shares more than 75% of identity with hST6Gal II cDNA coding sequence. The bovine gene, located on BTA 11, spans over 50 kbp with five exons (E1–E5) containing the 1488 bp open reading frame and a 5'-untranslated exon (E0). The gene expression pattern reveals a specific tissue distribution (brain, lungs, spleen, salivary, and mammary glands) compared to ST6Gal I which is ubiquitously expressed. We identified for bovine ST6Gal II three kinds of transcripts which differ by their 5'-untranslated regions. Among them, two transcripts are brain specific whereas the third one is found in all of the tissues expressing the gene. Two pFlag-bST6Gal II vector constructions were separ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757052 Mon, 31 Aug 2009 23:00:00 +0100 2757052 http://www.medworm.com/index.php?rid=2757051&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1078%3Frss%3D1 Practical synthesis of tetrasaccharide sulfates, 6(GlcNAc)-O-Su-SiaLeX-OCH2CH2CH2NH2 and 6(Gal)-O-Su-SiaLeX-OCH2CH2CH2NH2 (Su SO3H), selectin ligands, and leu- kocyte trafficking agents is presented. Both sulfates were synthesized starting from the same precursor, protected SiaLex, by the conventional procedures of carbohydrate chemistry. The sulfated SiaLex derivative was modified at the spacer group to give 6(Gal)-O-Su-SiaLex- OCH2CH2CH2NH-COCH2CH2CCH, convenient for "click chemistry" mode conjugation with an azido carrier, particularly, for the synthesis of an immunogen. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757051 Mon, 31 Aug 2009 23:00:00 +0100 2757051 http://www.medworm.com/index.php?rid=2757050&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1068%3Frss%3D1 N-Acetylglucosamine-6-sulfotransferase-1 (GlcNAc6ST-1) is a Golgi-resident glycoprotein that is responsible for sulfation of the l-selectin ligand on endothelial cells. Here, we report the sites at which GlcNAc6ST-1 is modified with N-linked glycans and the effects that each glycan has on enzyme activity, specificity, and localization. We determined that glycans are added at three of four potential N-linked glycosylation sites: N196, N410, and N428. The N428 glycan is required for the production of sulfated cell surface glycans: cells expressing a mutant enzyme lacking this glycan were unable to sulfate the sialyl Lewis X tetrasaccharide or a putative extended core 1 O-linked glycan. The N196 and N410 glycans differentially affect sulfation of two different substrates: cells that express a... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757050 Mon, 31 Aug 2009 23:00:00 +0100 2757050 http://www.medworm.com/index.php?rid=2757049&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1056%3Frss%3D1 Malignant transformation of epithelial cells is frequently associated with the alteration of glycosylation pathways. Tn is a common tumor-associated carbohydrate antigen present in 90% of human carcinomas and its expression correlates with metastatic potential and poor prognosis. Despite its relevance, the functional role of Tn in tumor biology has not been firmly established probably for the lack of appropriate experimental tools. Our aims were to produce highly reactive monoclonal antibodies against Tn making use of synthetically produced Tn and to test their usefulness for in vivo imaging as well as to define their potential functional activity in tumor cell spread. We immunized mice with Tn clustered on cationized BSA and screened the positive hybridomas with Tn-biotinylated alginate. ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757049 Mon, 31 Aug 2009 23:00:00 +0100 2757049 http://www.medworm.com/index.php?rid=2757048&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2F1055%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757048 Mon, 31 Aug 2009 23:00:00 +0100 2757048 http://www.medworm.com/index.php?rid=2757047&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757047 Mon, 31 Aug 2009 23:00:00 +0100 2757047 http://www.medworm.com/index.php?rid=2757046&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757046 Mon, 31 Aug 2009 23:00:00 +0100 2757046 http://www.medworm.com/index.php?rid=2757045&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F10%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2757045 Mon, 31 Aug 2009 23:00:00 +0100 2757045 http://www.medworm.com/index.php?rid=2666929&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F1046%3Frss%3D1 In this study, we clarified that this heterodisaccharide functions as an inducer of the production of the two above-mentioned chitinolytic enzymes, particularly chitinase. Similar results for chitinase production were obtained with other chitin-decomposing Vibrio strains harboring the CE family 4 COD gene; however, such an increase in chitinase production was not observed in chitinolytic Vibrio strains that did not harbor the COD gene. These results suggest that GlcNAc-GlcN is a unique inducer of chitinase production in Vibrio bacteria that have the COD-producing ability and that the COD involved in the synthesis of this signal compound is one of the key enzymes in the chitin catabolic cascade of these bacteria. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666929 Sun, 02 Aug 2009 23:00:00 +0100 2666929 http://www.medworm.com/index.php?rid=2666928&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F1034%3Frss%3D1 Galectins are a sub-family of lectins, defined by their highly conserved β-sandwich structures and ability to bind to β-galactosides, like Gal β1-4 Glc (lactose). Here, we used 15N-1H HSQC and pulse field gradient (PFG) NMR spectroscopy to demonstrate that galectin-1 (gal-1) binds to the relatively large galactomannan Davanat, whose backbone is composed of β1-4-linked d-mannopyranosyl units to which single d-galactopyranosyl residues are periodically attached via 1-6 linkage (weight-average MW of 59 kDa). The Davanat binding domain covers a relatively large area on the surface of gal-1 that runs across the dimer interface primarily on that side of the protein opposite to the lactose binding site. Our data show that gal-1 binds Davanat with an apparent equilibrium dissoc... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666928 Sun, 02 Aug 2009 23:00:00 +0100 2666928 http://www.medworm.com/index.php?rid=2666927&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F1018%3Frss%3D1 The structures of glycosphingolipids from highly purified colorectal cancer cells and normal colorectal epithelial cells of 16 patients have been analyzed in fine detail (Misonou Y, Shida K, Korekane H, Seki Y, Noura S, Ohue M, Miyamoto Y. 2009. Comprehensive Clinico-Glycomic Study of 16 Colorectal Cancer Specimens: Elucidation of aberrant glycosylation and ts mechanistic causes in colorectal cancer cells. J Proteome Res. 8:2990–3005). Further structural analyses demonstrated that colon cancer cells from two patients accumulated unusual glycosphingolipids which were not observed in either colorectal cancer cells or normal colorectal epithelial cells from the other patients. Mass spectrometry analyses revealed that the unusual structures include sulfated oligosaccharides. The structur... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666927 Sun, 02 Aug 2009 23:00:00 +0100 2666927 http://www.medworm.com/index.php?rid=2666926&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F1010%3Frss%3D1 Bifidobacteria are predominant bacteria present in the intestines of breast-fed infants and offer important health benefits for the host. Human milk oligosaccharides are one of the most important growth factors for bifidobacteria and are frequently fucosylated at their non-reducing termini. Previously, we identified 1,2--l-fucosidase (AfcA) belonging to the novel glycoside hydrolase (GH) family 95, from Bifidobacterium bifidum JCM1254 (Katayama T, Sakuma A, Kimura T, Makimura Y, Hiratake J, Sakata K, Yamanoi T, Kumagai H, Yamamoto K. 2004. Molecular cloning and characterization of Bifidobacterium bifidum 1,2--l-fucosidase (AfcA), a novel inverting glycosidase (glycoside hydrolase family 95). J Bacteriol. 186:4885–4893). Here, we identified a gene encoding a novel 1,3–1,4--l-fuc... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666926 Sun, 02 Aug 2009 23:00:00 +0100 2666926 http://www.medworm.com/index.php?rid=2666925&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F1002%3Frss%3D1 Effective enzyme replacement therapy for lysosomal storage diseases requires a recombinant enzyme with highly phosphorylated N-glycans. Recombinant human β-hexosaminidase A is a potentially therapeutic enzyme for GM2-gangliosidosis. Recombinant HexA has been produced by using the methylotrophic yeast Ogataea minuta as a host, and the purified enzyme was tested for its replacement effect on cultured fibroblasts derived from GM2-gangliosidosis patients. Although the therapeutic effect was observed, in order to obtain the higher therapeutic effect with a little dose as possible, increased phosphorylation of recombinant β-hexosaminidase A N-glycans is suggested to be prerequisite. In the budding yeast Saccharomyces cerevisiae, the overexpression of MNN4, which encodes a positive regu... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666925 Sun, 02 Aug 2009 23:00:00 +0100 2666925 http://www.medworm.com/index.php?rid=2666924&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F995%3Frss%3D1 Flocculosin is an unusual cellobiose lipid secreted by the yeast-like fungus Pseudozyma flocculosa as part of its biocontrol arsenal against other fungi. Recent observations have suggested that the fungus degrades flocculosin to use it as a nutrient source during periods of food limitation. In this work, we sought to identify the catabolic steps leading to the degradation of flocculosin and its subsequent use by P. flocculosa. To this end, we characterized the catabolism of flocculosin through identification of degradation intermediates in a deprived medium using mass spectrometry. As the pH of the medium increased, the molecule was quickly deacylated and lost its antimicrobial activity thereby explaining conflicting results concerning the antimicrobial activity of this class of glycolipid... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666924 Sun, 02 Aug 2009 23:00:00 +0100 2666924 http://www.medworm.com/index.php?rid=2666923&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F987%3Frss%3D1 During N-glycosylation of proteins, significant amounts of free unconjugated glycans are also generated in the lumen of the endoplasmic reticulum (ER). These ER-derived free glycans are translocated into the cytosol by a putative transporter on the ER membrane for further processing. However, the molecular nature of the transporter remains to be determined. Here, we report the establishment of a novel assay method for free oligosaccharide transport from the ER lumen using chemically synthesized fluorescence-labeled N-glycan derivatives. In this method, fluorescence-labeled glycan substrates were encapsulated inside mouse liver microsomes, followed by incubation with the cytosol and a fluorescence-quenching agent (anti-fluorophore antibody). The rate of substrate efflux was then monitored i... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666923 Sun, 02 Aug 2009 23:00:00 +0100 2666923 http://www.medworm.com/index.php?rid=2666922&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F971%3Frss%3D1 Inactivating mutations of Large reduce the functional glycosylation of -dystroglycan (-DG) and lead to muscular dystrophy in mouse and humans. The N-terminal domain of Large is most similar to UDP-glucose glucosyltransferases (UGGT), and the C-terminal domain is related to the human i blood group transferase β1,3GlcNAcT-1. The amino acids at conserved motifs DQD+1 and DQD+3 in the UGGT domain are necessary for mammalian UGGT activity. When the corresponding residues were mutated to Ala in mouse Large, -DG was not functionally glycosylated. A similar result was obtained when a DXD motif in the β1,3GlcNAcT-1 domain was mutated to AIA. Therefore, the first putative glycosyltransferase domain of Large has properties of a UGGT and the second of a typical glycosyltransferase. Co-transf... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666922 Sun, 02 Aug 2009 23:00:00 +0100 2666922 http://www.medworm.com/index.php?rid=2666921&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F958%3Frss%3D1 Alzheimer's disease (AD) is the most prevalent form of age-related neurodementia. The accumulation of β-amyloid polypeptide (Aβ) in brain is generally believed to be a key event in AD. The recent discovery of physiological β-amyloid autoantibodies represents a promising perspective for treatment and early diagnosis of AD. The mechanisms by which natural β-amyloid autoantibodies prevent neurodegeneration are currently unknown. The aim of the present study was to analyze the N-linked glycosylation of a plaque-specific, monoclonal antibody (clone 6E10) relevant for immunotherapy of AD, in comparison with the glycosylation pattern of an Aβ autoantibody isolated from an IgG source. Liquid chromatography in combination with tandem mass spectrometry was used to analyze th... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666921 Sun, 02 Aug 2009 23:00:00 +0100 2666921 http://www.medworm.com/index.php?rid=2666920&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F950%3Frss%3D1 In this report, we investigated the localizations of the molecular species of seminolipid by imaging mass spectrometry and demonstrated that major molecule (C16:0-alkyl-C16:0-acyl) was expressed throughout the tubules: some (C16:0-alkyl-C14:0-acyl and C14:0-alkyl-C16:0-acyl) were predominantly expressed in spermatocytes and the other (C17:0-alkyl-C16:0-acyl) was specifically expressed in spermatids and spermatozoa. This is the first report to show the cell-specific localization of each molecular species of seminolipid during testicular maturation. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666920 Sun, 02 Aug 2009 23:00:00 +0100 2666920 http://www.medworm.com/index.php?rid=2666919&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F936%3Frss%3D1 In the biopharmaceutical industry, mammalian cell culture systems, especially Chinese hamster ovary (CHO) cells, are predominantly used for the production of therapeutic glycoproteins. Glycosylation is a critical protein quality attribute that can modulate the efficacy of a commercial therapeutic glycoprotein. Obtaining a consistent glycoform profile in production is desired due to regulatory concerns because a molecule can be defined by its carbohydrate structures. An optimal profile may involve a spectrum of product glycans that confers a desired therapeutic efficacy, or a homogeneous glycoform profile that can be systemically screened for. Studies have shown some degree of protein glycosylation control in mammalian cell culture, through cellular, media, and process effects. Studies upon... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666919 Sun, 02 Aug 2009 23:00:00 +0100 2666919 http://www.medworm.com/index.php?rid=2666918&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2F935%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666918 Sun, 02 Aug 2009 23:00:00 +0100 2666918 http://www.medworm.com/index.php?rid=2666917&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666917 Sun, 02 Aug 2009 23:00:00 +0100 2666917 http://www.medworm.com/index.php?rid=2666916&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666916 Sun, 02 Aug 2009 23:00:00 +0100 2666916 http://www.medworm.com/index.php?rid=2666915&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F9%2Fi%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2666915 Sun, 02 Aug 2009 23:00:00 +0100 2666915 http://www.medworm.com/index.php?rid=2569344&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F918%3Frss%3D1 Trypanosoma cruzi, the causative agent of Chagas disease, is surrounded by a mucin coat that plays important functions in parasite survival/invasion and is extensively O-glycosylated by Golgi and cell surface glycosyltransferases. The addition of the first sugar, -N-acetylglucosamine (GlcNAc) linked to Threonine (Thr), is catalyzed by a polypeptide -GlcNAc-transferase (pp-GlcNAcT) which is unstable to purification. Here, a comparison of the genomes of T. cruzi and Dictyostelium discoideum, an amoebazoan which also forms this linkage, identified two T. cruzi genes (TcOGNT1 and TcOGNT2) that might encode this activity. Though neither was able to complement the Dictyostelium gene, expression in the trypanosomatid Leishmania tarentolae resulted in elevated levels of UDP-[3H]GlcNAc:Thr-peptide ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569344 Tue, 30 Jun 2009 23:00:00 +0100 2569344 http://www.medworm.com/index.php?rid=2569343&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F910%3Frss%3D1 We describe an ALG9-defective (congenital disorders of glycosylation type IL) patient who is homozygous for the p.Y286C (c.860A>G) mutation. This patient presented with psychomotor retardation, axial hypotonia, epilepsy, failure to thrive, inverted nipples, hepatomegaly, and pericardial effusion. Due to the ALG9 deficiency, the cells of this patient accumulated the lipid-linked oligosaccharides Man6GlcNAc2-PP-dolichol and Man8GlcNAc2-PP-dolichol. It is known that the oligosaccharide structure has a profound effect on protein glycosylation. Therefore, we investigated the influence of these truncated oligosaccharide structures on the protein transfer efficiency, the quality control of newly synthesized glycoproteins, and the eventual degradation of the truncated glycoproteins formed in th... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569343 Tue, 30 Jun 2009 23:00:00 +0100 2569343 http://www.medworm.com/index.php?rid=2569342&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F899%3Frss%3D1 GalMBP is a fragment of serum mannose-binding protein that has been modified to create a probe for galactose-containing ligands. Glycan array screening demonstrated that the carbohydrate-recognition domain of GalMBP selectively binds common groups of tumor-associated glycans, including Lewis-type structures and T antigen, suggesting that engineered glycan-binding proteins such as GalMBP represent novel tools for the characterization of glycoproteins bearing tumor-associated glycans. Blotting of cell extracts and membranes from MCF7 breast cancer cells with radiolabeled GalMBP was used to demonstrate that it binds to a selected set of high molecular weight glycoproteins that could be purified from MCF7 cells on an affinity column constructed with GalMBP. Proteomic and glycomic analysis of t... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569342 Tue, 30 Jun 2009 23:00:00 +0100 2569342 http://www.medworm.com/index.php?rid=2569341&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F890%3Frss%3D1 In this study, we demonstrate that pulse stimulation of mouse embryonic fibroblasts with high-molecular-weight (HMW) HA, but not HA of lower molecular sizes, leads to increases in Snail2 protein which are dependent on NFB activity. Involvement of CD44, the main HA receptor, in these responses was determined by use of a CD44 blocking antibody and CD44 siRNA. Both the blockade and silencing of CD44 significantly abrogate the increases in nuclear factor kappaB (NFB) activity and Snail2 protein following HMW-HA stimulation. Furthermore, we show that HMW-HA induces cellular invasion and that inhibition of CD44, Snail2, or NFB significantly decreases this response. These studies elucidate a novel HA/Snail2 functional connection through CD44 and NFB that is important for the induction of cellular... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569341 Tue, 30 Jun 2009 23:00:00 +0100 2569341 http://www.medworm.com/index.php?rid=2569340&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F879%3Frss%3D1 A central event in the formation of infectious prions is the conformational change of a host-encoded glycoprotein, PrPC, into a pathogenic isoform, PrPSc. The molecular requirements for efficient PrP conversion remain unknown. Altered glycosylation has been linked to various pathologies and the N-glycans harbored by two prion protein isoforms are different. In order to search for glycosylation-related genes that could mark prion infection, we used a glycosylation-dedicated microarray that allowed the simultaneous analysis of the expression of 165 glycosylation-related genes encoding proteins of the glycosyltransferase, glycosidase, lectin, and sulfotransferase families to compare the gene expression profiles of normal and scrapie-infected mouse brain and spleen. Eight genes were found upre... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569340 Tue, 30 Jun 2009 23:00:00 +0100 2569340 http://www.medworm.com/index.php?rid=2569339&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F868%3Frss%3D1 Carbohydrates are known to play essential roles in various biological processes including development. However, it remains largely unknown which carbohydrate structure takes part in each biological event. Here, we examined the roles of the human natural killer-1 (HNK-1) carbohydrate in medaka embryogenesis. We first cloned two medaka glucuronyltransferases, GlcAT-P and GlcAT-S, key enzymes for HNK-1 biosynthesis. Overexpression of these glucuronyltransferases affected morphogenetic processes. In addition, loss-of-function experiments revealed that GlcAT-P is physiologically indispensable for head morphogenesis and GlcAT-P depletion also led to markedly increased apoptosis. However, even when the apoptosis was blocked, abnormal head morphogenesis caused by GlcAT-P depletion was still observ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569339 Tue, 30 Jun 2009 23:00:00 +0100 2569339 http://www.medworm.com/index.php?rid=2569338&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F860%3Frss%3D1 In conclusion, marine sponges display an ancestor event of cell–cell adhesion, based on the calcium-dependent carbohydrate–carbohydrate interaction. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569338 Tue, 30 Jun 2009 23:00:00 +0100 2569338 http://www.medworm.com/index.php?rid=2569337&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F847%3Frss%3D1 We have previously shown that varicella-zoster virus (VZV) and cytomegalovirus (CMV) infection of diploid human fibroblasts (HEL) results in neo-expression of Lewis antigens sialyl Lewis x (sLex) and Lewis y (Ley), respectively, after transcriptional activation of different combinations of dormant human fucosyltransferase genes (FUT1, FUT3, FUT5, and FUT6), whose gene products are responsible for the synthesis of Le antigens. Here, we show that herpes simplex virus type 1 (HSV-1) also induces sLex expression dependent on induction of FUT3, FUT5, and FUT6 transcription in infected cells. HSV-1 induction of FUT5 was subsequently used as a model system for analyzing the mechanism of viral activation of dormant fucosyltransferase genes. We show that this is a rapid process, which gives rise to... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569337 Tue, 30 Jun 2009 23:00:00 +0100 2569337 http://www.medworm.com/index.php?rid=2569336&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F841%3Frss%3D1 Human Siglec-14, a member of the Siglec family of sialic acid-binding lectins, shows extensive sequence similarity to human Siglec-5. To analyze respective expression patterns of Siglec-14 and Siglec-5, we developed specific antibodies against each of them. We found that the former was expressed on granulocytes and monocytes, while the latter was on granulocytes and B-cells. Surprisingly, some individuals lacked the expression of Siglec-14, while they all expressed Siglec-5. We found that a fusion between SIGLEC14 and SIGLEC5 genes, resulting in the functional deletion of SIGLEC14, underlies this phenotype. The presence of the "SIGLEC14 null" allele in all human populations we tested implies an ancient origin, while its allelic frequency is higher in Asians compared with Africans and Europ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569336 Tue, 30 Jun 2009 23:00:00 +0100 2569336 http://www.medworm.com/index.php?rid=2569335&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F834%3Frss%3D1 We report here an in vivo enzymatic analysis using gene disruptants lacking either the G-II - or β-subunit in the filamentous fungus Aspergillus oryzae. Using synthetic oligosaccharides as probes, G-II activity of the membranous fraction of the gene disruptants was investigated. The fraction lacking the β-subunit retained hydrolytic activity toward p-nitrophenyl -d-glucopyranoside but was inactive toward both Glc2Man9GlcNAc2 and Glc1Man9GlcNAc2. When the fraction containing the β-subunit was added to the one including the -subunit, the glucosidase activity was restored. These results suggested that the β-subunit confers the substrate specificity toward di- and monoglucosylated glycans on the glucose-trimming activity of the -subunit. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569335 Tue, 30 Jun 2009 23:00:00 +0100 2569335 http://www.medworm.com/index.php?rid=2569334&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F829%3Frss%3D1 This article demonstrates that in the mouse and human the predominant XylT in serum is XylT2. Furthermore, that total XylT levels in human serum are approximately 200% higher than those in plasma due in part to XylT released by platelets during blood clotting in vitro. In addition, the data from Xylt2 knock-out mice and mice with liver neoplasia show that liver is a significant source of serum XylT2 activity. The data presented suggest that serum XylT levels may be an informative biomarker in patients who suffer from diseases affecting platelet and/or liver homeostasis. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569334 Tue, 30 Jun 2009 23:00:00 +0100 2569334 http://www.medworm.com/index.php?rid=2569333&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F816%3Frss%3D1 Protein O-mannosylation is an essential modification in fungi and animals. Different from most other types of O-glycosylation, protein O-mannosylation is initiated in the endoplasmic reticulum by the transfer of mannose from dolichol monophosphate-activated mannose to serine and threonine residues of secretory proteins. In recent years, it has emerged that even bacteria are capable of O-mannosylation and that the biosynthetic pathway of O-mannosyl glycans is conserved between pro- and eukaryotes. In this review, we summarize the observations that have opened up the field and highlight characteristics of O-mannosylation in the different domains/kingdoms of life. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569333 Tue, 30 Jun 2009 23:00:00 +0100 2569333 http://www.medworm.com/index.php?rid=2569332&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F813%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569332 Tue, 30 Jun 2009 23:00:00 +0100 2569332 http://www.medworm.com/index.php?rid=2569331&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F810%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569331 Tue, 30 Jun 2009 23:00:00 +0100 2569331 http://www.medworm.com/index.php?rid=2569330&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2F809%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569330 Tue, 30 Jun 2009 23:00:00 +0100 2569330 http://www.medworm.com/index.php?rid=2569329&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2Fiii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569329 Tue, 30 Jun 2009 23:00:00 +0100 2569329 http://www.medworm.com/index.php?rid=2569328&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F19%2F8%2Fii%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=2569328 Tue, 30 Jun 2009 23:00:00 +0100 2569328