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. Mon, 06 Feb 2012 14:26:13 +0100 http://www.medworm.com/index.php?rid=5635260&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F439%3Frss%3D1 Glucuronoxylans with a backbone of 1,4-linked β-d-xylosyl residues are ubiquitous in the secondary walls of gymnosperms and angiosperms. Xylans have been reported to be present in hornwort cell walls, but their structures have not been determined. In contrast, the presence of xylans in the cell walls of mosses and liverworts remains a subject of debate. Here we present data that unequivocally establishes that the cell walls of leafy tissue and axillary hair cells of the moss Physcomitrella patens contain a glucuronoxylan that is structurally similar to glucuronoxylans in the secondary cell walls of vascular plants. Some of the 1,4-linked β-d-xylopyranosyl residues in the backbone of this glucuronoxylan bear an α-d-glucosyluronic acid (GlcpA) sidechain at O-2. In contrast, t... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635260 Fri, 27 Jan 2012 05:00:00 +0100 5635260 http://www.medworm.com/index.php?rid=5635259&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F429%3Frss%3D1 Mucin-type glycosylation [α-N-acetyl-d-galactosamine (α-GalNAc)-O-Ser/Thr] on proteins is initiated biosynthetically by 16 homologous isoforms of GalNAc-Ts (uridine diphosphate-GalNAc:polypeptide N-acetylgalactosaminyltransferases). All the GalNAc-Ts consist of a catalytic domain and a lectin domain. Previous reports of GalNAc-T assays toward peptides and α-GalNAc glycopeptides showed that the lectin domain recognized the sugar on the substrates and affected the reaction; however, the details are not clear. Here, we report a new strategy to give insight on the sugar recognition ability and the function of the GalNAc-T3 lectin domain using chemically synthesized natural-type (α-GalNAc-O-Thr) and unnatural-type [β-GalNAc-O-Thr, α-Fuc-O-Thr and β-GlcNAc... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635259 Fri, 27 Jan 2012 05:00:00 +0100 5635259 http://www.medworm.com/index.php?rid=5635258&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F417%3Frss%3D1 The inability to produce recombinant glycoproteins with authentic N-glycans is a limitation of many heterologous protein expression systems. In the baculovirus–insect cell system, this limitation has been addressed by glycoengineering insect cell lines with mammalian genes encoding protein N-glycosylation functions ("glycogenes") under the transcriptional control of constitutive promoters. However, a potential problem with this approach is that the metabolic load imposed by the expression of multiple transgenes could adversely impact the growth and/or stability of glycoengineered insect cell lines. Thus, we created a new transgenic insect cell line (SfSWT-5) with an inducibly mammalianized protein N-glycosylation pathway. Expression of all six glycogenes was induced when uninfected S... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635258 Fri, 27 Jan 2012 05:00:00 +0100 5635258 http://www.medworm.com/index.php?rid=5635257&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F411%3Frss%3D1 It is known that disialic acids (diSia) are present in the mammalian brain. However, the precise anatomical distribution and the chronology of its expression along life are not well studied yet. It is accepted that the transfer of diSia in the brain is mediated mainly by the enzyme ST8Sia III (α2,8-sialyltransferase III). We studied the expression of diSia glycoepitopes and of the ST8Sia III gene in different structures of the mouse brain at different postnatal stages by immunohistochemistry and real-time polymerase chain reaction, respectively. C57BL/6 mice of different stages were used. Samples of hippocampus, olfactory bulb, cortex and cerebellum were processed for studies of molecular biology and immunohistochemistry. Histological analysis revealed an important decrease in diSia ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635257 Fri, 27 Jan 2012 05:00:00 +0100 5635257 http://www.medworm.com/index.php?rid=5635256&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F400%3Frss%3D1 In conclusion, our results suggest a role for 4-MU as an anticancer agent for HCC associated with advanced fibrosis. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635256 Fri, 27 Jan 2012 05:00:00 +0100 5635256 http://www.medworm.com/index.php?rid=5635255&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F389%3Frss%3D1 Oligomannosidic (OM) N-glycans occur as a mixture of isomers, which at early stages of glycosidase trimming also comprise structures with one to three glucose residues. A complementary set of isomers is generated during the biosynthesis of the lipid-linked precursor. Here, we demonstrate the remarkable capacity of liquid chromatography (LC) with porous graphitic carbon and mass spectrometric detection for the determination of OM isomers. Protein-linked N-glycans were released enzymatically from samples with known isomer composition such as kidney bean proteins and ribonuclease B. Lipid-linked oligosaccharides were obtained by a direct mild acid hydrolysis of microsomes thus avoiding biphasic partitioning. A parallel analysis of pyridylaminated glycans by amide-silica and reversed-phase hig... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635255 Fri, 27 Jan 2012 05:00:00 +0100 5635255 http://www.medworm.com/index.php?rid=5635254&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F379%3Frss%3D1 In recent years, sugars with a unique chemical handle have been used to detect and elucidate the function of glycoconjugates. Such chemical handles have generally been part of an N-acetyl moiety of a sugar. We have previously developed several applications using the single mutant Y289L-β1,4-galactosyltransferase I (Y289L-β4Gal-T1) and the wild-type polypeptide-α-GalNAc-T enzymes with UDP-C2-keto-Gal. Here, we describe for the first time that the GlcNAc-transferring enzymes—R228K-Y289L-β4Gal-T1 mutant enzyme, the wild-type human β1,3-N-acetylglucosaminyltransferase-2 and human Maniac Fringe—can also transfer the GlcNAc analog C2-keto-Glc molecule from UDP-C2-keto-Glc to their respective acceptor substrates. Although the R228K-Y289L-β4Gal-T1 mutant ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635254 Fri, 27 Jan 2012 05:00:00 +0100 5635254 http://www.medworm.com/index.php?rid=5635253&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F369%3Frss%3D1 In conclusion, our results suggest that hybrid- and complex-type N-glycans are not required for NDV infection and fusion. We propose that high-Man-type N-glycans could play an important role in the cell-to-cell fusion induced by NDV. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635253 Fri, 27 Jan 2012 05:00:00 +0100 5635253 http://www.medworm.com/index.php?rid=5635252&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F361%3Frss%3D1 The breast-fed infant intestine is often colonized by particular bifidobacteria, and human milk oligosaccharides (HMOs) are considered to be bifidogenic. Recent studies showed that Bifidobacterium longum subsp. infantis can grow on HMOs as the sole carbon source. This ability has been ascribed to the presence of a gene cluster (HMO cluster-1) contained in its genome. However, the metabolism of HMOs by the organism remains unresolved because no enzymatic studies have been completed. In the present study, we characterized β-galactosidases of this subspecies to understand how the organism degrades type-1 (Galβ1-3GlcNAc) and type-2 (Galβ1-4GlcNAc) isomers of HMOs. The results revealed that the locus tag Blon_2016 gene, which is distantly located from the HMO cluster-1, encodes a... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635252 Fri, 27 Jan 2012 05:00:00 +0100 5635252 http://www.medworm.com/index.php?rid=5635251&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F352%3Frss%3D1 It is now emerging the new concept that the antibodies from some patients with Guillain–Barré syndrome (GBS) recognize an antigenic epitope formed by two different gangliosides, a ganglioside complex (GSC). We prepared the dimeric GM1–GD1a hybrid ganglioside derivative that contains two structurally different oligosaccharide chains to mimic the GSC. We use this compound to analyze sera from GBS patients by high-performance thin-layer chromatography immunostaining and enzyme-linked immunosorbent assay. We also synthesized the dimeric GM1–GM1 and GD1a–GD1a compounds that were used in control experiments together with natural gangliosides. The hybrid dimeric GM1–GD1a was specifically recognized by human sera from GBS patients that developed anti-oligosacch... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635251 Fri, 27 Jan 2012 05:00:00 +0100 5635251 http://www.medworm.com/index.php?rid=5635250&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F345%3Frss%3D1 A class IV chitinase belonging to the glycoside hydrolase 19 family from Nepenthes alata (NaCHIT1) was expressed in Escherichia coli. The enzyme exhibited weak activity toward polymeric substrates and significant activity toward (GlcNAc)n [β-1,4-linked oligosaccharide of GlcNAc with a polymerization degree of n (n = 4–6)]. The enzyme hydrolyzed the third and fourth glycosidic linkages from the non-reducing end of (GlcNAc)6. The pH optimum of the enzymatic reaction was 5.5 at 37°C. The optimal temperature for activity was 60°C in 50 mM sodium acetate buffer (pH 5.5). The anomeric form of the products indicated that it was an inverting enzyme. The kcat/Km of the (GlcNAc)n hydrolysis increased with an increase in the degree of polymerization. Amino acid seque... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635250 Fri, 27 Jan 2012 05:00:00 +0100 5635250 http://www.medworm.com/index.php?rid=5635249&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F332%3Frss%3D1 In this study, we have determined the core OS of the LPS expressed by the Heddleston serovar 9 type strain, P2095. Structural information was established by a combination of monosaccharide and methylation analyses, nuclear magnetic resonance spectroscopy and mass spectrometry revealing the following structure: . The serovar 9 OS contains an inner core that is conserved among P. multocida strains with an elaborate outer core extension containing rhamnose (Rha), a d-glycero-d-manno isomer of heptose, and the unusual deoxyamino sugar, 3-acetamido-3,6-dideoxy-α-d-glucose (Qui3NAc). Genetic analyses of the LPS outer core biosynthesis locus revealed that in addition to the glycosyltransferases predicted to transfer the sugars to the nascent LPS molecule, the locus also contained the compl... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635249 Fri, 27 Jan 2012 05:00:00 +0100 5635249 http://www.medworm.com/index.php?rid=5635248&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F326%3Frss%3D1 The affinity of the d-galactose-binding lectin from Artocarpus heterophyllus lectin, known as jacalin, with immonuglobulins (Igs) was determined by biofunctionalization of a piezoelectric transducer. This piezoelectric biofunctionalized transducer was used as a mass-sensitive analytical tool, allowing the real-time binding analysis of jacalin–human immunoglobulin A1 (IgA1) and jacalin–bovine IgG1 interactions from which the apparent affinity constant was calculated. The strategy was centered in immobilizing jacalin on the gold electrode's surface of the piezoelectric crystal resonator using appropriate procedures based on self-assembling of 11-mercaptoundecanoic acid and 2-mercaptoethanol thiol's mixture, a particular immobilization strategy by which it was possible to avoid cr... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635248 Fri, 27 Jan 2012 05:00:00 +0100 5635248 http://www.medworm.com/index.php?rid=5635247&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F318%3Frss%3D1 Phage display technology is an emerging drug discovery tool. Using that approach, short peptides that mimic part of a carbohydrate's conformation are selected by screening a peptide-displaying phage library with anti-carbohydrate antibodies. Chemically synthesized peptides with an identified sequence have been used as an alternative ligand to carbohydrate-binding proteins. These peptides represent research tools useful to assay the activities of glycosyltransferases and/or sulfotransferases or to inhibit the carbohydrate-dependent binding of proteins in vitro and in vivo. Peptides can also serve as immunogens to raise anti-carbohydrate antibodies in vivo in animals. Phage display has also been used in single-chain antibody technology by inserting an immunoglobulin's variable region sequenc... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635247 Fri, 27 Jan 2012 05:00:00 +0100 5635247 http://www.medworm.com/index.php?rid=5635246&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2F315%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635246 Fri, 27 Jan 2012 05:00:00 +0100 5635246 http://www.medworm.com/index.php?rid=5635245&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635245 Fri, 27 Jan 2012 05:00:00 +0100 5635245 http://www.medworm.com/index.php?rid=5635244&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635244 Fri, 27 Jan 2012 05:00:00 +0100 5635244 http://www.medworm.com/index.php?rid=5635243&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F3%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5635243 Fri, 27 Jan 2012 05:00:00 +0100 5635243 http://www.medworm.com/index.php?rid=5592815&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F300%3Frss%3D1 In this study, we present both mass spectrometric and high-performance liquid chromatography data about the N-glycans of different strains of Trichomonas vaginalis, a parasite of the human reproductive tract. The major structure in all strains examined is a truncated oligomannose form (Man5GlcNAc2) with α1,2-mannose residues, compatible with a previous bioinformatic examination of the glycogenomic potential of T. vaginalis. In addition, dependent on the strain, N-glycans modified by pentose residues, phosphate or phosphoethanolamine and terminal N-acetyllactosamine (Galβ1,4GlcNAc) units were found. The modification of N-glycans by N-acetyllactosamine in at least some strains is shared with the lipo(phospho)glycan and may represent a further interaction partner for host galectins... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592815 Wed, 11 Jan 2012 05:00:00 +0100 5592815 http://www.medworm.com/index.php?rid=5592814&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F288%3Frss%3D1 WaaL is a membrane enzyme that catalyzes a key step in lipopolysaccharide (LPS) synthesis: the glycosidic bonding of a sugar at the proximal end of the undecaprenyl-diphosphate (Und-PP) O-antigen with a terminal sugar of the lipid A-core oligosaccharide (OS). Utilizing an in vitro assay, we demonstrate here that ligation with purified Escherichia coli WaaL occurs without adenosine-5'-triphosphate (ATP) and magnesium ions. Furthermore, E. coli and Pseudomonas aeruginosa WaaL proteins cannot catalyze ATP hydrolysis in vitro. We also show that a lysine substitution of the arginine (Arg)-215 residue renders an active protein, whereas WaaL mutants with alanine replacements in the periplasmic-exposed residues Arg-215, Arg-288 and histidine (His)-338 and also the membrane-embedded aspartic acid-3... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592814 Wed, 11 Jan 2012 05:00:00 +0100 5592814 http://www.medworm.com/index.php?rid=5592813&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F281%3Frss%3D1 The O-antigen is one of the most variable Gram-negative cell constituents, and its specificity is important for bacterial niche adaptation. The observed diversity of O-antigen forms is mainly due to genetic variations in O-antigen gene clusters. Less common is a change of gene function due to nucleotide substitution; a new instance of which is reported here. The O-antigens of E. coli O107 and O117 have similar structures differing only in a single sugar residue (GlcNAc in O107 substituted for Glc in O117). These O-antigen gene clusters contain the same set of 11 genes and share 98.6% overall DNA identity. The function of the genes in the gene clusters have been proposed previously, and a glycosyltransferase gene (wclY) with nucleotide polymorphism in each strain was proposed to transfer di... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592813 Wed, 11 Jan 2012 05:00:00 +0100 5592813 http://www.medworm.com/index.php?rid=5592812&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F267%3Frss%3D1 We present new specific targets for human ficolin-3, identified among lipopolysaccharides (LPSs, endotoxin) of Hafnia alvei. The interaction was restricted to LPSs of four strains: 23, Polish Collection of Microorganisms (PCM) 1200, PCM 1203 and PCM 1205 and limited to their O-specific polysaccharides (O-specific PSs) composed of different numbers of oligosaccharide (OS) repeating units (RUs). Moreover, these LPS/ficolin-3 complexes activated the lectin pathway of complement in a C4b-deposition assay in a calcium- and magnesium-dependent way. A neoglycoconjugate of the O-specific PS fraction of H. alvei 1200 LPS with bovine serum albumin (BSA) was prepared and used as a tool for the determination of ficolin-3 concentration and activity in serum. To confirm a structure of the O-specific PS ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592812 Wed, 11 Jan 2012 05:00:00 +0100 5592812 http://www.medworm.com/index.php?rid=5592811&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F258%3Frss%3D1 ZG16p is a soluble 16 kDa pancreatic protein having structural similarities with plant β-prism fold lectins such as the banana lectin BanLec and the jackfruit lectin jacalin. ZG16p is postulated to be involved in the formation of zymogen granules by interacting with proteoglycans (PGs) localized in pancreatic exocrine granule membranes, but direct evidence was lacking. We characterized the structural properties of rat pancreatic zymogen granule PGs and examined their interaction with ZG16p. Structural analysis of the glycosaminoglycans (GAGs) showed that rat pancreatic zymogen granule PGs have heparan sulfate chains with a unique property, a high degree of sulfation (UA-GlcNAc:UA-GlcNS:UA-GlcNAc6S:UA-GlcNS6S:UA2S-GlcNS:UA2S-GlcNS6S, 27.9:16.6:5.7:22.5:6.2:21.1). After heparin lya... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592811 Wed, 11 Jan 2012 05:00:00 +0100 5592811 http://www.medworm.com/index.php?rid=5592810&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F248%3Frss%3D1 Glycosaminoglycans were extracted from both young rabbit growth plate (GRP) and articular (ART) cartilage tissues and enzymatically treated to selectively eliminate chondroitin sulfates and hyaluronic acid. The procedure avoided any fractionation step that could enrich the extract with over- or under-sulfated species. Isolated heparan sulfate (HS) was characterized by mono- and bidimensional nuclear magnetic resonance (NMR) spectroscopy to quantify their specific structural features and/or by mass spectrometry to establish the disaccharide composition. Both GRP and ART HSs, despite differing in their yield (GRP at least 100 times greater than ART), exhibited a surprisingly high degree of sulfation. Quantitative two-dimensional heteronuclear single-quantum coherence-NMR analysis of GRP HS r... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592810 Wed, 11 Jan 2012 05:00:00 +0100 5592810 http://www.medworm.com/index.php?rid=5592809&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F235%3Frss%3D1 In this study, we overexpressed LARGE in neural stem cells deficient in protein O-mannosyltransferase 2 (POMT2), an enzyme required for O-mannosyl glycosylation. The results showed that overexpressing LARGE did not lead to hyperglycosylation of α-DG in POMT2 knockout (KO) cells but did generate IIH6C4 and VIA4-1 immunoreactivity and laminin-binding activity. Additionally, overexpressing LARGE in cells deficient in both POMT2 and α-DG generated laminin-binding IIH6C4 immunoreactivity. These results indicate that LARGE expression resulted in the glycosylation of proteins other than α-DG in the absence of O-mannosyl glycosylation. The IIH6C4 immunoreactivity generated in double-KO cells was largely removed by treatment either with peptide N-glycosidase F or with cold aqueous... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592809 Wed, 11 Jan 2012 05:00:00 +0100 5592809 http://www.medworm.com/index.php?rid=5592808&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F221%3Frss%3D1 Glycation of immunoglobulin G (IgG) can result from incubation with a reducing sugar in vitro or during circulation in vivo. Upon injection of a recombinantly produced human therapeutic IgG into humans, changes in the glycation levels could be observed as a function of circulation time. Mass changes on the individual IgG polypeptide chains as the results of glycation were determined using reversed-phase liquid chromatography/mass spectrometry. Changes to the light and heavy chains were low but easily detectable at 0.00092 and 0.0021 glucose (Glc) additions per chain per day, respectively. Levels of glycation found on the Fc portion of IgG isolated from healthy subjects, using a similar analytical approach, were on average 0.045 Glc molecules per fragment. In vivo glycation rates could be a... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592808 Wed, 11 Jan 2012 05:00:00 +0100 5592808 http://www.medworm.com/index.php?rid=5592807&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F210%3Frss%3D1 Human zymogen granule protein 16 (ZG16p) contains a Jacalin-like lectin domain, although its glycan-binding properties are not fully understood. Here, we screened the glycan-binding specificity of ZG16p by recently developed glycoconjugate microarray. ZG16p appeared to exhibit selective binding to α- and β-linked mannose-polyacrylamide-biotin probes. In more quantitative analysis using frontal affinity chromatography, dissociation constants to two types of polyvalent mannose, i.e. high-density mannose and yeast mannan, were determined to be 1.3 and 1.7 µM, respectively. Mutation of the evolutionarily conserved amino acid Asp151, which is involved in sugar binding among the Jacalin-related lectins (JRLs), abolished binding activity to mannose. By immunohistochemical st... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592807 Wed, 11 Jan 2012 05:00:00 +0100 5592807 http://www.medworm.com/index.php?rid=5592806&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F196%3Frss%3D1 Polysialic acid (polySia) is mainly described as a glycan modification of the neural cell adhesion molecule NCAM1. PolySia-NCAM1 has multiple functions during the development of vertebrate nervous systems including axon extension and fasciculation. Phylogenetic analyses reveal the presence of two related gene clusters, NCAM1 and NCAM2, in tetrapods and fishes. Within the ncam1 cluster, teleost fishes express ncam1a (ncam) and ncam1b (pcam) as duplicated paralogs which arose from a second round of ray-finned fish-specific genome duplication. Tetrapods, in contrast, express a single NCAM1 gene. Using the zebrafish model, we identify Ncam1b as a novel major carrier of polySia in the nervous system. PolySia-Ncam1a is expressed predominantly in rostral regions of the developing nervous system, ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592806 Wed, 11 Jan 2012 05:00:00 +0100 5592806 http://www.medworm.com/index.php?rid=5592805&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F181%3Frss%3D1 In this study, we determined the carbohydrate structures of KL-6/MUC1 to search the carbohydrate epitopes for KL-6/mAb. KL-6/MUC1 was purified from the culture medium of human breast cancer YMB-S cells by KL-6/mAb-affinity chromatography; the O-linked glycan structures were determined in combination with paper electrophoresis, several lectin column chromatographies, sialidase digestion and methanolysis. KL-6/MUC1 contained core 1 and extended core 1 glycans modified with one or two sialic acid/sulfate residues. Based on these structures, several synthetic glycans binding to anti-KL-6/mAb were compared with one another by surface plasmon resonance. Sequentially, related radiolabeled oligosaccharides were enzymatically synthesized and analyzed for binding to a KL-6/mAb-conjugated affinity co... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592805 Wed, 11 Jan 2012 05:00:00 +0100 5592805 http://www.medworm.com/index.php?rid=5592804&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F174%3Frss%3D1 The hemagglutinin–neuraminidase (HN) glycoprotein is utilized by human parainfluenza viruses for binding to the host cell. By the use of glycan array assays, we demonstrate that, in addition to the first catalytic-binding site, the HN of human parainfluenza virus type 1 has a second site for binding covered by N-linked glycan. Our data suggest that attachment of the first site to sialic acid (SA)-linked receptors triggers exposure of the second site. We found that both sites bind to α2-3-linked SAs with a preference for a sialyl-Lewisx motif. Binding to α2-3-linked SAs with a sulfated sialyl-Lewis motif as well as to α2-8-linked SAs was unique for the second binding site. Neither site recognizes α2-6-linked oligosaccharides. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592804 Wed, 11 Jan 2012 05:00:00 +0100 5592804 http://www.medworm.com/index.php?rid=5592803&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2F171%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592803 Wed, 11 Jan 2012 05:00:00 +0100 5592803 http://www.medworm.com/index.php?rid=5592802&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592802 Wed, 11 Jan 2012 05:00:00 +0100 5592802 http://www.medworm.com/index.php?rid=5592801&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592801 Wed, 11 Jan 2012 05:00:00 +0100 5592801 http://www.medworm.com/index.php?rid=5592800&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F2%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5592800 Wed, 11 Jan 2012 05:00:00 +0100 5592800 http://www.medworm.com/index.php?rid=5482906&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F160%3Frss%3D1 Glycan-binding proteins are commonly used as analytical reagents to detect the levels of specific glycan structures in biological samples. A detailed knowledge of the specificities of glycan-binding proteins is required for properly interpreting their binding data. A powerful technology for characterizing glycan-binding specificity is the glycan array. However, the interpretation of glycan-array data can be difficult due to the complex fine specificities of certain glycan-binding proteins. We developed a systematic approach, called outlier-motif analysis, for extracting fine-specificity information from glycan-array data, and we applied the method to the study of four commonly used lectins: two mannose binders (concanavalin A and Lens culinaris) and two galactose binders (Bauhinia purpurea... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482906 Mon, 05 Dec 2011 05:00:00 +0100 5482906 http://www.medworm.com/index.php?rid=5482905&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F146%3Frss%3D1 We prepared enzymatically synthesized glycogen (ESG) with the same characteristics as natural glycogen and investigated whether the macrophage-stimulating activity of glycogen was related to Toll-like receptors (TLRs), which are important receptors for innate immunity. ESG induced no nuclear factor-kappa B (NF-B) activity in TLR4/MD-2/CD14-expressed human embryonic kidney 293 (HEK293) reporter cells, whereas this polysaccharide did activate peritoneal exude cells (PECs) derived from TLR4-deficient mice at the same level as those from wild-type (WT) mice. Similarly, ESG did not activate HEK293 cells expressing TLR3, 5, 7, 8 or 9, suggesting that these TLRs were irrelevant to the activity of ESG. In contrast, ESG enhanced the NF-B activity of TLR2-expressed HEK293 reporter cells in a concent... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482905 Mon, 05 Dec 2011 05:00:00 +0100 5482905 http://www.medworm.com/index.php?rid=5482904&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F134%3Frss%3D1 The interactions between glycosaminoglycans (GAGs), important components of the extracellular matrix, and proteins such as growth factors and chemokines play critical roles in cellular regulation processes. Therefore, the design of GAG derivatives for the development of innovative materials with bio-like properties in terms of their interaction with regulatory proteins is of great interest for tissue engineering and regenerative medicine. Previous work on the chemokine interleukin-8 (IL-8) has focused on its interaction with heparin and heparan sulfate, which regulate chemokine function. However, the extracellular matrix contains other GAGs, such as hyaluronic acid (HA), dermatan sulfate (DS) and chondroitin sulfate (CS), which have so far not been characterized in terms of their distinct ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482904 Mon, 05 Dec 2011 05:00:00 +0100 5482904 http://www.medworm.com/index.php?rid=5482903&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F123%3Frss%3D1 This study supports the hypothesis that the ability of a cryoprotectant to inhibit ice recrystallization is an important property to enhance cell viability post-freeze-thaw. This cryoprotective benefit is observed in three different human cell lines. Furthermore, we demonstrated that the ability of a potential cryoprotectant to inhibit ice recrystallation may be used as a predictor of its ability to preserve cells at subzero temperatures. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482903 Mon, 05 Dec 2011 05:00:00 +0100 5482903 http://www.medworm.com/index.php?rid=5482902&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F116%3Frss%3D1 We report here the purification and biochemical characterization of the WbaP C-terminal (WbaPCT) domain harboring one putative transmembrane helix and a large cytoplasmic tail. An N-terminal thioredoxin fusion greatly improved solubility and stability of WbaPCT allowing us to obtain highly purified protein. We demonstrate that WbaPCT is sufficient to catalyze the in vitro transfer of galactose (Gal)-1-phosphate from uridine monophosphate (UDP)-Gal to the lipid carrier undecaprenyl monophosphate (Und-P). We optimized the in vitro assay to determine steady-state kinetic parameters with the substrates UDP-Gal and Und-P. Using various purified polyisoprenyl phosphates of increasing length and variable saturation of the isoprene units, we also demonstrate that the purified enzyme functions high... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482902 Mon, 05 Dec 2011 05:00:00 +0100 5482902 http://www.medworm.com/index.php?rid=5482901&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F107%3Frss%3D1 The polysialic acid (PSA) moiety of the neural cell adhesion molecule (NCAM) has been shown to support dynamic changes underlying peripheral nerve regeneration. Using transgenic mice expressing polysialyltransferase ST8SiaIV under control of a glial-specific (proteolipid protein, PLP) promoter (PLP-ST8SiaIV-transgenic mice), we tested the hypothesis that permanent synthesis of PSA in Schwann cells impairs functional recovery of lesioned peripheral nerves. After sciatic nerve crush, histomorphometric analyses demonstrated impaired remyelination of regenerated axons at the lesion site and in target tissue of PLP-ST8SiaIV-transgenic mice, though the number and size of regenerating unmyelinated axons were not changed. This was accompanied by slower mechanosensory recovery in PLP-ST8SiaIV-trans... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482901 Mon, 05 Dec 2011 05:00:00 +0100 5482901 http://www.medworm.com/index.php?rid=5482900&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F96%3Frss%3D1 Heparan sulfate (HS) and heparin are highly sulfated polysaccharides exhibiting essential physiological functions. The sulfation patterns determine the functional selectivity for HS and heparin. Chemical synthesis of HS, especially those larger than a hexasaccharide, remains challenging. Enzymatic synthesis of HS has recently gained momentum. Here we describe the divergent assembly of HS heptasaccharides and nonasaccharides from a common hexasaccharide precursor. The hexasaccharide precursor was synthesized via a chemical method. The subsequent elongation, sulfation and epimerization were completed by glycosyltransferases, HS sulfotransferases and epimerase. Using the synthesized heptasaccharides, we discovered that the iduronic acid is critical for binding to fibroblast growth factor-2. W... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482900 Mon, 05 Dec 2011 05:00:00 +0100 5482900 http://www.medworm.com/index.php?rid=5482899&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F84%3Frss%3D1 Ischemia/reperfusion (I/R) is an important cause of acute renal failure. Recent studies have shown that the complement system mediated by the mannan-binding protein (MBP), which is a C-type serum lectin recognizing mannose, fucose and N-acetylglucosamine residues, plays a critical role in the pathogenesis of ischemic acute renal failure. MBP causes complement activation through the MBP lectin pathway and a resulting complement component, C3b, is accumulated on the brush borders of kidney proximal tubules in a renal I/R-operated mouse kidney. However, the initial step of the complement activation has not been studied extensively. We previously identified both meprins α and β, highly glycosylated zinc metalloproteases, localized on kidney proximal tubules as endogenous MBP ligands... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482899 Mon, 05 Dec 2011 05:00:00 +0100 5482899 http://www.medworm.com/index.php?rid=5482898&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F70%3Frss%3D1 Enhanced expression of 9-O-acetylated sialoglycoproteins (Neu5,9Ac2-GPs) and 9-O-acetylated disialoganglioside (9-OAcGD3) was observed on lymphoblasts of childhood acute lymphoblastic leukemia (ALL). Sialate-O-acetyltransferase (SOAT) and sialate-O-acetylesterase (SIAE) are the two main enzymes responsible for the quantity of the O-acetyl ester groups on sialic acids (Sias). We have earlier shown an enhanced level of SOAT activity, capable of transferring acetyl groups to Sias of glycoconjugates in the microsomes of lymphoblasts of these children. We further observed a decreased SIAE activity in both lysosomal and cytosolic fractions of ALL cell lines and primary cells from bone marrow of patients compared with peripheral blood mononuclear cells from healthy donors, which preferentially hy... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482898 Mon, 05 Dec 2011 05:00:00 +0100 5482898 http://www.medworm.com/index.php?rid=5482897&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F56%3Frss%3D1 The crystal structure of a β-prism II (BP2) fold lectin from Remusatia vivipara, a plant of traditional medicinal value, has been determined at a resolution of 2.4 Å. This lectin (RVL, Remusatia vivipara lectin) is a dimer with each protomer having two distinct BP2 domains without a linker between them. It belongs to the "monocot mannose-binding" lectin family, which consists of proteins of high sequence and structural similarity. Though the overall tertiary structure is similar to that of lectins from snowdrop bulbs and garlic, crucial differences in the mannose-binding regions and oligomerization were observed. Unlike most of the other structurally known proteins in this family, only one of the three carbohydrate recognition sites (CRSs) per BP2 domain is found to be cons... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482897 Mon, 05 Dec 2011 05:00:00 +0100 5482897 http://www.medworm.com/index.php?rid=5482896&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F35%3Frss%3D1 Mammalian heparanase is an endo-β-glucuronidase associated with cell invasion in cancer metastasis, angiogenesis and inflammation. Heparanase cleaves heparan sulfate proteoglycans in the extracellular matrix and basement membrane, releasing heparin/heparan sulfate oligosaccharides of appreciable size. This in turn causes the release of growth factors, which accelerate tumor growth and metastasis. Heparanase has two glycosaminoglycan-binding domains; however, no three-dimensional structure information is available for human heparanase that can provide insights into how the two domains interact to degrade heparin fragments. We have constructed a new homology model of heparanase that takes into account the most recent structural and bioinformatics data available. Heparin analogs and glyc... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482896 Mon, 05 Dec 2011 05:00:00 +0100 5482896 http://www.medworm.com/index.php?rid=5482895&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F23%3Frss%3D1 The glycoside hydrolase 18 (GH18) family of chitinases is a multigene family that plays various roles, such as ecdysis, embryonic development, allergic inflammation and so on. Efforts are still needed to reveal their functional diversification in an evolutionary and systematic manner. We collected 85 GH18 genes from eukaryotic representatives. The domain architectures of GH18 proteins were analyzed and several conserved patterns were identified. It was observed that some (11 proteins) GH18 members in Ecdysozoa or fungi possess repeats of catalytic domains and/or chitin-binding domains (ChtBs). The domain repeats are likely to meet requirements for higher efficiency of chitin degradation in chitin-containing species. On the contrary, all vertebrate GH18 proteins contain no more than one cat... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482895 Mon, 05 Dec 2011 05:00:00 +0100 5482895 http://www.medworm.com/index.php?rid=5482894&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F12%3Frss%3D1 In allergic diseases such as asthma, eosinophils, basophils and mast cells, through release of preformed and newly generated mediators, granule proteins and cytokines, are recognized as key effector cells. While their surface protein phenotypes, mediator release profiles, ontogeny, cell trafficking and genomes have been generally explored and compared, there has yet to be any thorough analysis and comparison of their glycomes. Such studies are critical to understand the contribution of carbohydrates to the induction and regulation of allergic inflammatory responses and are now possible using improved technologies for detecting and characterizing cell-derived glycans. We thus report here the application of high-sensitivity mass spectrometric-based glycomics methodologies to the analysis of ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482894 Mon, 05 Dec 2011 05:00:00 +0100 5482894 http://www.medworm.com/index.php?rid=5482893&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F7%3Frss%3D1 Hyaluronan (HA) is a linear non-sulfated polysaccharide mainly found in the extracellular matrix. The size of HA can vary from a few disaccharides up to at least 25,000 units, reaching molecular weights of 10 103 kDa. HA has many biological functions, and both its size and tissue concentration play an important role in many physiological and pathological processes. It is relatively easy to determine the HA concentration using enzyme-linked binding protein assays, but the molecular weight of HA has so far been shown to be a more challenging task to measure. Here, we present a method for size determination of HA using gas-phase electrophoretic mobility molecular analysis (GEMMA), which utilizes the electrophoretic mobility of molecules in air to estimate the molecular weight of the... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482893 Mon, 05 Dec 2011 05:00:00 +0100 5482893 http://www.medworm.com/index.php?rid=5482892&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F3-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482892 Mon, 05 Dec 2011 05:00:00 +0100 5482892 http://www.medworm.com/index.php?rid=5482891&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F3%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482891 Mon, 05 Dec 2011 05:00:00 +0100 5482891 http://www.medworm.com/index.php?rid=5482890&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2F1%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482890 Mon, 05 Dec 2011 05:00:00 +0100 5482890 http://www.medworm.com/index.php?rid=5482889&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482889 Mon, 05 Dec 2011 05:00:00 +0100 5482889 http://www.medworm.com/index.php?rid=5482888&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482888 Mon, 05 Dec 2011 05:00:00 +0100 5482888 http://www.medworm.com/index.php?rid=5482887&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F22%2F1%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5482887 Mon, 05 Dec 2011 05:00:00 +0100 5482887 http://www.medworm.com/index.php?rid=5417337&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1663%3Frss%3D1 The human M3 muscarinic acetylcholine receptor is present in both the central and peripheral nervous system, and it is involved in the pathophysiology of several neurodegenerative and autoimmune diseases. We suggested a possible N-glycosylation map for the M3 muscarinic receptor expressed in COS-7 cells. Here, we examined the role that N-linked glycans play in the folding and in the cell surface trafficking of this receptor. The five potential asparagine-linked glycosylation sites in the muscarinic receptor were mutated and transiently expressed in COS-7 cells. The elimination of N-glycan attachment sites did not affect the cellular expression levels of the receptor. However, proper receptor localization to the plasma membrane was affected as suggested by reduced [3H]-N-methylscopolamine b... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417337 Thu, 17 Nov 2011 05:00:00 +0100 5417337 http://www.medworm.com/index.php?rid=5417336&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1651%3Frss%3D1 Understanding microsecond-timescale dynamics is crucial to establish three-dimensional (3D) structure–activity relationships in sugars but has been intractable to experiments and simulations. As a consequence, whether arguably the most important chemical scaffold in glycobiology, N-acetyl-d-glucosamine (GlcNAc), deviates from a rigid 4C1 chair is unknown. Here, conformer populations and exchange kinetics were quantified from the longest aqueous carbohydrate simulations to date (0.2 ms total) of GlcNAc, four derivatives from heparan sulfate and their methylglycosides. Unmodified GlcNAc took 3–5 μs to reach a conformational equilibrium, which comprised a metastable 4C1 chair that underwent 4C1  1C4 transitions at a predicted forward rate of 0.8 μs&n... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417336 Thu, 17 Nov 2011 05:00:00 +0100 5417336 http://www.medworm.com/index.php?rid=5417335&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1642%3Frss%3D1 Antibodies to the ganglioside GM1 are associated with various forms of acute and chronic immune-mediated neuropathy, including Guillain–Barré syndrome (GBS) and multifocal motor neuropathy. In diagnostics and research, these antibodies are usually detected by GM1 preparations derived from bovine brain tissue, which are non-covalently attached to solid carriers such as enzyme-linked immunosorbent assay (ELISA) plates. Such brain-derived GM1 preparations are potentially contaminated with other glycolipids. In the current study, uncontaminated mono- and divalent synthetic analogs of the ganglioside GM1 were successfully attached via covalent bonds onto the surface of ELISA plates. The resulting modified diagnostic tool showed strong affinities and good specificities for binding o... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417335 Thu, 17 Nov 2011 05:00:00 +0100 5417335 http://www.medworm.com/index.php?rid=5417334&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1627%3Frss%3D1 By definition, adhesion/growth-regulatory galectins are known for their ability to bind β-galactosides such as Galβ(1 -> 4)Glc (lactose). Indications for affinity of human galectin-1 to α-linked digalactosides pose questions on the interaction profile with such bound ligands and selection of the galactose moiety for CH– stacking. These issues are resolved by a combination of 15N–1H heteronuclear single quantum coherence (HSQC) chemical shift and saturation transfer difference nuclear magnetic resonance (STD NMR) epitope mappings with docking analysis, using the α(1 -> 3/4)-linked digalactosides and also Galα(1 -> 6)Glc (melibiose) as test compounds. The experimental part revealed interaction with the canonical l... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417334 Thu, 17 Nov 2011 05:00:00 +0100 5417334 http://www.medworm.com/index.php?rid=5417333&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1616%3Frss%3D1 The methylotrophic yeast, Pichia pastoris, is an important organism used for the production of therapeutic proteins. However, the presence of fungal-like glycans, such as those containing β-mannose (Man) linkages, can elicit an immune response or bind to Man receptors, thus reducing their efficacy. Recent studies have confirmed that P. pastoris has four genes from the β-mannosyl transferase (BMT) family and that Bmt2p is responsible for the majority of β-Man linkages on glycans. While expressing recombinant human erythropoietin (rhEPO) in a developmental glycoengineered strain devoid of BMT2 gene expression, cross-reactivity was observed with an antibody raised against host cell antigens. Treatment of the rhEPO with protein N-glycosidase F eliminated cross-reactivity, indica... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417333 Thu, 17 Nov 2011 05:00:00 +0100 5417333 http://www.medworm.com/index.php?rid=5417332&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1606%3Frss%3D1 The N-glycosylation pathway in Pichia pastoris has been humanized by the deletion of genes responsible for fungal-type glycosylation (high mannose) as well as the introduction of heterologous genes capable of forming human-like N-glycosylation. This results in a yeast host that is capable of expressing therapeutic glycoproteins. A thorough investigation was performed to examine whether glycoproteins expressed in glycoengineered P. pastoris strains may contain residual fungal-type high-mannose structures. In a pool of N-linked glycans enzymatically released by protein N-glycosidase from a reporter glycoprotein expressed in a developmental glycoengineered P. pastoris strain, an oligosaccharide with a mass consistent with a Hexose9GlcNAc2 oligosaccharide was identified. When this structure wa... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417332 Thu, 17 Nov 2011 05:00:00 +0100 5417332 http://www.medworm.com/index.php?rid=5417331&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1596%3Frss%3D1 In this study, we demonstrated that another type of polySia, the α2,8-linked polyNeu5Ac, exclusively occurs on O-glycans of a 190 kDa glycoprotein (190 kDa-gp), whereas the α2,9-linked polyNeu5Ac is exclusively present on flagellasialin. The 190 kDa-gp is localized in both flagellum and head of sperm. We also demonstrated that polysialogangliosides containing the α2,8-linked polyNeu5Ac are present in sperm head. Thus, this study shows two novel features of the occurrence of polySia in nature, the co-localization of polySia with different intersialyl linkages, the α2,8- and α2,9-linkages, in a single cell and the occurrence of α2,8-linked polyNeu5Ac in glycolipids. Anti-α2,8-linked polyNeu5Ac antibody had no effect on fertilization, w... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417331 Thu, 17 Nov 2011 05:00:00 +0100 5417331 http://www.medworm.com/index.php?rid=5417330&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1588%3Frss%3D1 It was established in a mouse model that the cowshed Gram-positive bacterium Lactococcus lactis G121 modulates the immune system resulting in allergy protection. However, the molecules and mechanisms involved in this process have not been elucidated yet. Lipoteichoic acids (LTAs) represent one major cell envelope component of Gram-positive bacteria that is considered a pathogen-associated molecular pattern. In the investigations presented here, the isolation as well as the structural and functional analyses of the LTA of L. lactis G121 were performed. Extraction with butan-1-ol and purification by hydrophobic interaction chromatography yielded pure LTA. Structural investigations included chemical analytical methods, nuclear magnetic resonance spectroscopy and high-resolution electrospray i... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417330 Thu, 17 Nov 2011 05:00:00 +0100 5417330 http://www.medworm.com/index.php?rid=5417329&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1580%3Frss%3D1 A skin mucus lectin exhibiting a homodimeric structure and an S–S bond between subunits of ~40 kDa was purified from flathead Platycephalus indicus (Scorpaeniformes). This lectin, named FHL (FlatHead Lectin), exhibited mannose-specific activity in a Ca2+-dependent manner. Although FHL showed no homology to any previously reported lectins, it did exhibit ~20% identity to previously discovered plasma kallikreins and coagulation factor XIs of mammals and Xenopus laevis. These known proteins are serine proteases and play pivotal roles in the kinin-generating system or the blood coagulation pathway. However, alignment analysis revealed that while FHL lacked a serine protease domain, it was homologous to the heavy-chain domain of plasma kallikreins and coagulation factor XI therefore ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417329 Thu, 17 Nov 2011 05:00:00 +0100 5417329 http://www.medworm.com/index.php?rid=5417328&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1570%3Frss%3D1 Carbohydrates are likely to maintain significant conformational flexibility in antibody (Ab):carbohydrate complexes. As demonstrated herein for the protective monoclonal Ab (mAb) F22-4 recognizing the Shigella flexneri 2a O-antigen (O-Ag) and numerous synthetic oligosaccharide fragments thereof, the combination of molecular dynamics simulations and nuclear magnetic resonance saturation transfer difference experiments, supported by physicochemical analysis, allows us to determine the binding epitope and its various contributions to affinity without using any modified oligosaccharides. Moreover, the methods used provide insights into ligand flexibility in the complex, thus enabling a better understanding of the Ab affinities observed for a representative set of synthetic O-Ag fragments. Addi... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417328 Thu, 17 Nov 2011 05:00:00 +0100 5417328 http://www.medworm.com/index.php?rid=5417327&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1554%3Frss%3D1 Cell surface lectin staining, examination of Golgi glycosyltransferases stability and localization, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis were employed to investigate conserved oligomeric Golgi (COG)-dependent glycosylation defects in HeLa cells. Both Griffonia simplicifolia lectin-II and Galanthus nivalus lectins were specifically bound to the plasma membrane glycoconjugates of COG-depleted cells, indicating defects in activity of medial- and trans-Golgi-localized enzymes. In response to siRNA-induced depletion of COG complex subunits, several key components of Golgi glycosylation machinery, including MAN2A1, MGAT1, B4GALT1 and ST6GAL1, were severely mislocalized. MALDI-TOF analysis of total N-linked glycoconjugates indicated a decrease in the... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417327 Thu, 17 Nov 2011 05:00:00 +0100 5417327 http://www.medworm.com/index.php?rid=5417326&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1541%3Frss%3D1 There is a growing use of bioinformatics based methods in the field of Glycobiology. These have been used largely to curate glycan structures, organize array-based experimental data and display existing knowledge of glycosylation-related pathways in silico. Although the cataloging of vast amounts of data is beneficial, it is often a challenge to gain meaningful mechanistic insight from this exercise alone. The development of specific analysis tools to query the database is necessary. If these queries can integrate existing knowledge of glycobiology, new insights may be gained. Such queries that couple biochemical knowledge and mathematics have been developed in the field of Systems Biology. The current review summarizes the current state of the art in the application of computational model... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417326 Thu, 17 Nov 2011 05:00:00 +0100 5417326 http://www.medworm.com/index.php?rid=5417325&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2F1539%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417325 Thu, 17 Nov 2011 05:00:00 +0100 5417325 http://www.medworm.com/index.php?rid=5417324&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417324 Thu, 17 Nov 2011 05:00:00 +0100 5417324 http://www.medworm.com/index.php?rid=5417323&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417323 Thu, 17 Nov 2011 05:00:00 +0100 5417323 http://www.medworm.com/index.php?rid=5417322&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F12%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5417322 Thu, 17 Nov 2011 05:00:00 +0100 5417322 http://www.medworm.com/index.php?rid=5343416&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1438%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5343416 Thu, 20 Oct 2011 04:00:00 +0100 5343416 http://www.medworm.com/index.php?rid=5343415&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1432%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5343415 Thu, 20 Oct 2011 04:00:00 +0100 5343415 http://www.medworm.com/index.php?rid=5343414&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1429%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5343414 Thu, 20 Oct 2011 04:00:00 +0100 5343414 http://www.medworm.com/index.php?rid=5310582&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1532%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310582 Wed, 12 Oct 2011 04:00:00 +0100 5310582 http://www.medworm.com/index.php?rid=5310581&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1454%3Frss%3D1 Cell surface mucins configure the cell surface by presenting extended protein backbones that are heavily O-glycosylated. The glycopeptide structures establish physicochemical properties at the cell surface that enable and block the formation of biologically important molecular complexes. Some mucins, such as MUC1, associate with receptor tyrosine kinases and other cell surface receptors, and engage in signal transduction in order to communicate information regarding conditions at the cell surface to the nucleus. In that context, the MUC1 cytoplasmic tail (MUC1CT) receives phosphorylation signals from receptor tyrosine kinases and serine/threonine kinases, which enables its association with different signaling complexes that conduct these signals to the nucleus and perhaps other subcellular... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310581 Wed, 12 Oct 2011 04:00:00 +0100 5310581 http://www.medworm.com/index.php?rid=5310580&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1416%3Frss%3D1 In conclusion, no major differences were observed for N-glycan structures obtained by the expressed model proteins in the apical and basolateral secretory pathways of epithelial MDCK cells, but insertion of a GAG attachment domain shifted the N-glycans to more acidic structures. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310580 Wed, 12 Oct 2011 04:00:00 +0100 5310580 http://www.medworm.com/index.php?rid=5310579&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1401%3Frss%3D1 Here, we present a comparative structure–function study of a nematode and a plant core α1,3-fucosyltransferase based on deletion and point mutations of the coding regions of Caenorhabditis elegans FUT-1 and Arabidopsis thaliana FucTA (FUT11). In particular, our results reveal a novel "first cluster motif" shared by both core and Lewis-type α1,3-fucosyltransferases of the GT10 family. To evaluate the role of the conserved serine within this motif, this residue was replaced with alanine in FucTA (S218) and FUT-1 (S243). The S218A replacement completely abolished the enzyme activity of FucTA, while the S243A mutant of FUT-1 retained 20% of the "wild-type" activity. Based on the results of homology modeling of FucTA, other residues potentially involved in the donor substrate ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310579 Wed, 12 Oct 2011 04:00:00 +0100 5310579 http://www.medworm.com/index.php?rid=5310578&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1395%3Frss%3D1 Asparagine N-linked glycosylation is one of the most important forms of protein post-translational modification in eukaryotes and is one of the first metabolic pathways described at a biochemical level. Here, we report a new annotation of this pathway for the Human species, published after passing a peer-review process in Reactome. The new annotation presented here offers a high level of detail and provides references and descriptions for each reaction, along with integration with GeneOntology and other databases. The open-source approach of Reactome toward annotation encourages feedback from its users, making it easier to keep the annotation of this pathway updated with future knowledge. Reactome's web interface allows easy navigation between steps involved in the pathway to compare it wi... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310578 Wed, 12 Oct 2011 04:00:00 +0100 5310578 http://www.medworm.com/index.php?rid=5310577&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1393%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310577 Wed, 12 Oct 2011 04:00:00 +0100 5310577 http://www.medworm.com/index.php?rid=5310576&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1390%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310576 Wed, 12 Oct 2011 04:00:00 +0100 5310576 http://www.medworm.com/index.php?rid=5310575&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2F1389%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310575 Wed, 12 Oct 2011 04:00:00 +0100 5310575 http://www.medworm.com/index.php?rid=5310574&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310574 Wed, 12 Oct 2011 04:00:00 +0100 5310574 http://www.medworm.com/index.php?rid=5310573&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310573 Wed, 12 Oct 2011 04:00:00 +0100 5310573 http://www.medworm.com/index.php?rid=5310572&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F11%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5310572 Wed, 12 Oct 2011 04:00:00 +0100 5310572 http://www.medworm.com/index.php?rid=5203952&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1382%3Frss%3D1 Two different mutated forms of BRI2 protein are linked with familial British and Danish dementias, which present neuropathological similarities with Alzheimer's disease. BRI2 is a type II transmembrane protein that is trafficked through the secretory pathway to the cell surface and is processed by furin and ADAM10 (a disintegrin and metalloproteinase domain 10) to release secreted fragments of unknown function. Its apparent molecular mass (42–44 kDa) is significantly higher than that predicted by the number and composition of amino acids (30 kDa) suggesting that BRI2 is glycosylated. In support, bioinformatics analysis indicated that BRI2 bears the consensus sequence Asn-Thr-Ser (residues 170–173) and could be N-glycosylated at Asn170. Given that N-glycosylation is co... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203952 Tue, 06 Sep 2011 04:00:00 +0100 5203952 http://www.medworm.com/index.php?rid=5203951&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1373%3Frss%3D1 Gangliosides (sialic acid-containing glycosphingolipids) play important roles in many physiological functions, including synaptic plasticity in the hippocampus, which is considered as a cellular mechanism of learning and memory. In the present study, three types of synaptic plasticity, long-term potentiation (LTP), long-term depression (LTD) and reversal of LTP (depotentiation, DP), in the field excitatory post-synaptic potential in CA1 hippocampal neurons and learning behavior were examined in β1,4-N-acetylgalactosaminyltransferase (β1,4 GalNAc-T; GM2/GD2 synthase) gene transgenic (TG) mice, which showed a marked decrease in b-pathway gangliosides (GQ1b, GT1b and GD1b) in the brain and isolated hippocampus compared with wild-type (WT) mice. The magnitude of the LTP induced by te... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203951 Tue, 06 Sep 2011 04:00:00 +0100 5203951 http://www.medworm.com/index.php?rid=5203950&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1362%3Frss%3D1 Bacteria Shigella, the cause of shigellosis, evolved from the intestinal bacteria Escherichia coli. Based on structurally diverse O-specific polysaccharide chains of the lipopolysaccharides (LPSs; O-antigens), three from four Shigella species are subdivided into multiple serotypes. The central oligosaccharide of the LPS called core is usually conserved within genus but five core types called R1–R4 and K-12 have been recognized in E. coli. Structural data on the Shigella core are limited to S. sonnei, S. flexneri and one S. dysenteriae strain, which all share E. coli core types. In this work, we elucidated the core structure in 14 reference strains of S. dysenteriae and S. boydii. Core oligosaccharides were obtained by mild acid hydrolysis of the LPSs and studied using sugar analysis,... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203950 Tue, 06 Sep 2011 04:00:00 +0100 5203950 http://www.medworm.com/index.php?rid=5203949&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1349%3Frss%3D1 In this work, we analyzed at high resolution the sugar-binding mode of the recombinant N-terminal ricin-B domain of the hemolytic protein LSLa (LSL150) from the mushroom Laetiporus sulphureus and also provide functional in vitro evidence suggesting that, together with its putative receptor-binding role, this module may also increase the solubility of its membrane pore-forming partner. We first demonstrate that recombinant LSL150 behaves as an autonomous folding unit and an active lectin. We have determined its crystal structure at 1.47 Å resolution and also that of the [LSL150:(lactose)β, )] binary complex at 1.67 Å resolution. This complex reveals two lactose molecules bound to the β and sites of LSL150, respectively. Isothermal titration calorimetry indica... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203949 Tue, 06 Sep 2011 04:00:00 +0100 5203949 http://www.medworm.com/index.php?rid=5203948&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1341%3Frss%3D1 In this study, structural diversity of fOSs in och1 cells was analyzed. To our surprise, several fOSs in och1 cells have unusual α-1,3-linked mannose residues at their non-reducing termini. These mannose residues were not observed in wild-type cells, suggesting that the addition of these unique mannoses occurred as a compensation of Och1 defect. A significant increase in the amount of fOSs modified by Golgi-localized mannosyltransferases was also observed in och1 cells. Moreover, the amount of processed fOSs and intracellular α-mannosidase (Ams1) both increased in this mutant. Up-regulation of Ams1 activity was also apparent for cells treated with cell wall perturbation reagent. These results provide an insight into a possible link between catabolism of fOSs and cell wall stres... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203948 Tue, 06 Sep 2011 04:00:00 +0100 5203948 http://www.medworm.com/index.php?rid=5203947&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1331%3Frss%3D1 We describe here the cloning and analysis of a novel Comamonas GAG synthase, CtTS. The GAG produced by CtTS in vitro consists of the sugars d-GlcUA and N-acetyl-d-glucosamine, but is insensitive to digestion by GAG digesting enzymes, thus has distinct glycosidic linkages from vertebrate GAGs. The backbone structure of the polysaccharide product [-4-d-GlcUA-α1,4-d-GlcNAc-α1-]n was confirmed by nuclear magnetic resonance. Therefore, this novel GAG, testosteronan, consists of the same sugars as the biomedically relevant GAGs heparosan (N-acetyl-heparosan) and hyaluronan but may have distinct properties useful for future medical applications. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203947 Tue, 06 Sep 2011 04:00:00 +0100 5203947 http://www.medworm.com/index.php?rid=5203946&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1317%3Frss%3D1 Although the properties of milk oligosaccharides have been of scientific interest for many years, their structural diversity presents a challenging analytical task. In the quest for a simple and robust technology to characterize the different oligosaccharides present in milk, we developed an analytical scheme based on their fluorescent labeling, pre-fractionation by weak anionic exchange chromatography and separation by hydrophilic interaction liquid chromatography (HILIC)-high performance liquid chromatography (HPLC). HILIC relies on the hydrophilic potential of the molecule, which accounts for differences in properties such as molecular volume, lipophilic surface area, charge, composition, structure, linkage and oligosaccharide branching. The robustness of the methodology has been demons... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203946 Tue, 06 Sep 2011 04:00:00 +0100 5203946 http://www.medworm.com/index.php?rid=5203945&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1301%3Frss%3D1 Organ fibrosis is associated with excessive deposition of dermatan sulfate (DS) in the extracellular matrix (ECM) of the affected tissue. However, the significance of DS in fibrosis process is poorly known. Thus, we have analyzed both in vitro and in vivo the binding potential toward fibroblast growth factor-2, platelet-derived growth factor BB and fibronectin (FN) of DS representing glycosaminoglycan (GAG) chains of two proteoglycans decorin and biglycan derived from fascia undergoing fibrosis due to Dupuytren's disease. Moreover, to investigate the relation between DS structure and its binding properties to above ligands, we have also studied the interactions of the GAG chains from normal porcine skin decorin and biglycan. The examined interactions, especially those engaging extractable ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203945 Tue, 06 Sep 2011 04:00:00 +0100 5203945 http://www.medworm.com/index.php?rid=5203944&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1290%3Frss%3D1 The limited proteolysis of proteins by the proprotein convertases (PCs) is a common means of producing bioactive proteins or peptides. The PCs are associated with numerous human pathologies and their activity can be reduced through the use of specific inhibitors. Here, we demonstrate an alternative approach to inhibiting PCs by altering their N-glycosylation. Through site-directed mutagenesis, we show that the convertase PC1/3 contains two N-glycans, only one of which is critical for its prosegment cleavage. The exact structure of PC1/3 N-glycans does not significantly affect its zymogen activation within endocrine cells, but glycosylation of Asn146 is critical. Processing of the PC1/3's substrate proopiomelanocortin (POMC) was used in a cell-based assay to screen a collection of 45 compou... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203944 Tue, 06 Sep 2011 04:00:00 +0100 5203944 http://www.medworm.com/index.php?rid=5203943&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1277%3Frss%3D1 In this study, we examined the occurrence of α-anomeric TF (TFα) on a large variety of gastrointestinal bacteria using a novel panel of well-characterized monoclonal antibodies. Reactivity with at least one anti-TF antibody was found in 13% (16 of 122) of strains analyzed. A more in-depth analysis, using monoclonal antibodies specific for α- and β-anomeric TF in combination with periodate oxidation, revealed that only two novel Bacteroides ovatus strains (D-6 and F–1), isolated from the faeces of healthy persons by TF-immunoaffinity enrichment, possessed structures that are immunochemically identical to the true TFα antigen. The TF-positive capsular polysaccharide structure of strain D-6 was characterized by mass spectrometry, monosaccharide composition a... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203943 Tue, 06 Sep 2011 04:00:00 +0100 5203943 http://www.medworm.com/index.php?rid=5203942&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1266%3Frss%3D1 Morganella morganii is a commensal Gram-negative bacterium that has long been known to produce an antigen bearing phosphocholine groups. We determined the structure of this O-chain antigen and found that its repeating unit also contains a free amino group and a second phosphate: This alternating charge character places the M. morganii O-chain polysaccharide into a small family of zwitterionic polysaccharides (ZPSs) known to induce T-cell-dependent immune responses via presentation by class II major histocompatibility complex (MHCII) molecules. In vitro binding assays demonstrate that this O-chain interacts with MHCII in a manner that competes with binding of the prototypical ZPS antigen PSA from Bacteroides fragilis, despite its lack of a helical structure. Cellular studies also showed t... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203942 Tue, 06 Sep 2011 04:00:00 +0100 5203942 http://www.medworm.com/index.php?rid=5203941&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1258%3Frss%3D1 In this study, we show that galectin-9 is not limited to the role of a pro-apoptotic agent, but that it can also induce the production of pro-inflammatory cytokines from T helper cells. This effect is dose-dependent and does not require Tim-3. These findings suggest that the effects of galectin-9 on T cells are more complex than previously thought and are mediated by additional receptors apart from Tim-3. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203941 Tue, 06 Sep 2011 04:00:00 +0100 5203941 http://www.medworm.com/index.php?rid=5203940&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1257%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203940 Tue, 06 Sep 2011 04:00:00 +0100 5203940 http://www.medworm.com/index.php?rid=5203939&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2F1255%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203939 Tue, 06 Sep 2011 04:00:00 +0100 5203939 http://www.medworm.com/index.php?rid=5203938&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203938 Tue, 06 Sep 2011 04:00:00 +0100 5203938 http://www.medworm.com/index.php?rid=5203937&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203937 Tue, 06 Sep 2011 04:00:00 +0100 5203937 http://www.medworm.com/index.php?rid=5203936&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F10%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5203936 Tue, 06 Sep 2011 04:00:00 +0100 5203936 http://www.medworm.com/index.php?rid=5102684&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1237%3Frss%3D1 Oligoarabinofuranoside-containing glycolipids relevant to mycobacterial cell wall components were synthesized in order to understand the functional roles of such glycolipids. A series of linear tetra-, hexa-, octa- and a branched heptasaccharide oligoarabinofuranosides, with 1 -> 2 and 1 -> 5 α-linkages between the furanoside residues, were synthesized by chemical methods from readily available monomer building blocks. Upon the synthesis of glycolipids, constituted with a double alkyl chain-substituted sn-glycerol core and oligosaccharide fragments, biological studies were performed to identify the effect of synthetic glycolipids on the biofilm formation and sliding motilities of Mycobacterium smegmatis. Synthetic glycolipids and arabinofuranosides displayed... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102684 Wed, 03 Aug 2011 23:00:00 +0100 5102684 http://www.medworm.com/index.php?rid=5102683&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1228%3Frss%3D1 In this study, we demonstrate the synthesis of nucleotide sugars from corresponding monosaccharides in a highly efficient manner via metabolic engineering, using an enzymatic approach. This method exploits l-fucokinase/guanosine 5'-diphosphate (GDP)-l-fucose (L-Fuc) pyrophosphorylase (FKP), a bifunctional enzyme isolated from Bacteroides fragilis 9343, which converts l-Fuc into GDP-L-Fuc via an L-Fuc-1-phosphate intermediate. Because L-Fuc and d-arabinose (D-Ara) are structurally similar, it is assumed that the biosynthesis of GDP-D-Ara in a recombinant Saccharomyces cerevisiae strain harboring the FKP gene can occur through a mechanism akin to that of GDP-L-Fuc via the salvage pathway. Thus, we reasoned that by exogenously supplying different monosaccharides structurally related to L-Fuc,... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102683 Wed, 03 Aug 2011 23:00:00 +0100 5102683 http://www.medworm.com/index.php?rid=5102682&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1217%3Frss%3D1 The binding of recombinant fragments of the C-terminal cell-binding domains of the two large exotoxins, toxin A (TcdA) and toxin B (TcdB), expressed by Clostridium difficile and a library consisting of the most abundant neutral and acidic human milk oligosaccharides (HMOs) was examined quantitatively at 25°C and pH 7 using the direct electrospray ionization mass spectrometry (ES-MS) assay. The results of the ES-MS measurements indicate that both toxin fragments investigated, TcdB-B1 and TcdA-A2, which possess one and two carbohydrate binding sites, respectively, bind specifically to HMOs ranging in size from tri- to heptasaccharides. Notably, five of the HMOs tested bind to both toxins: Fuc(α1-2)Gal(β1-4)Glc, Gal(β1-3)GlcNAc(β1-3)Gal(β1-4)Glc, Fuc(α1-2)G... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102682 Wed, 03 Aug 2011 23:00:00 +0100 5102682 http://www.medworm.com/index.php?rid=5102681&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1206%3Frss%3D1 Pasteurella multocida (Pm) is a multi-species pathogen that causes diseases in animals and humans. Sialyltransferase activity has been detected in multiple Pm strains and sialylation has been shown to be important for the pathogenesis of Pm. Three putative sialyltransferase genes have been identified in Pm genomic strain Pm70. We have reported previously that a Pm0188 gene homolog in Pm strain P-1059 (ATCC 15742) encodes a multifunctional sialyltransferase (PmST1). We demonstrate here that while PmST1 prefers to use oligosaccharides as acceptors, PmST2 encoded by the Pm0508 gene homolog in the same Pm strain is a novel glycolipid α2-3-sialyltransferase that prefers to use lactosyl lipids as acceptor substrates. PmST2 and PmST1 thus complement each other for an efficient synthesis of ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102681 Wed, 03 Aug 2011 23:00:00 +0100 5102681 http://www.medworm.com/index.php?rid=5102680&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1194%3Frss%3D1 A series of size-defined low-molecular-weight heparins were generated by regioselective chemical modifications and profiled for their in vitro and in vivo activities. The compounds displayed reduced anti-coagulant activity, demonstrated varying affinities toward angiogenic growth factors (fibroblast growth factor-2, vascular endothelial growth factor and stromal cell-derived factor-1α), inhibited the P-selectin/P-selectin glycoprotein ligand-1 interaction and, notably, exhibited anti-tumor efficacy in a murine melanoma experimental metastasis model. Our results demonstrate that modulating specific sequences, especially the N-domains (–NS or –NH2 or –NHCOCH3) in these polysaccharide sequences, has a major impact on the participation in a diverse range of biological a... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102680 Wed, 03 Aug 2011 23:00:00 +0100 5102680 http://www.medworm.com/index.php?rid=5102679&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1181%3Frss%3D1 Heparan sulfate is a polysaccharide belonging to the glycaminoglycan family. It interacts with numerous proteins of the extracellular matrix, in particular cellular growth factors. The number of experimental protein–heparin sulfate complexes obtained by crystallography or nuclear magnetic resonance is limited. Alternatively, computational approaches can be employed. Generally, they restrain the conformation of the glycosidic rings and linkages in order to reduce the complexity of the problem. Modeling the interaction between protein and heparan sulfate is indeed challenging because of the large size of the fragment needed for a strong binding, the flexibility brought by the glycosidic rings and linkages and the high density of negative charges. We propose a two-step method based on m... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102679 Wed, 03 Aug 2011 23:00:00 +0100 5102679 http://www.medworm.com/index.php?rid=5102678&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1173%3Frss%3D1 We examined the effect of different media and culture temperatures on the molecular weight (Mw), polymer distribution and composition of cell wall mannan and mannoprotein complex. Strain SC5314 was inoculated from frozen stock onto yeast peptone dextrose (YPD), blood or 5% serum agar media at 30 or 37°C prior to mannan/mannoprotein extraction. Cultivation of the yeast in blood or serum at physiologic temperature resulted in an additive effect on Mw, however, cultivation media had the greatest impact on Mw. Mannan from a yeast grown on blood or serum at 30°C showed a 38.9 and 28.6% increase in Mw, when compared with mannan from YPD-grown yeast at 30°C. Mannan from the yeast pregrown on blood or serum at 37°C showed increased Mw (8.8 and 26.3%) when compared with YPD mannan a... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102678 Wed, 03 Aug 2011 23:00:00 +0100 5102678 http://www.medworm.com/index.php?rid=5102677&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1161%3Frss%3D1 GD3 (CD60a) and its 9-O-acetylated variant (CD60b) are intracellular regulators of apoptosis in T lymphocytes. Surface expressed 9-O-acetyl- and 7-O-acetyl-GD3 (CD60b and CD60c) may have a functional impact on activated T and B cells. In order to investigate the balance between surface and intracellular expression and synthesis and degradation of these glycosphingolipids in human lymphocytes of various differentiation stages, we analyzed (i) expression of GD3 molecules on native T and B cells and thymocytes by flow cytometry and (ii) activity and regulation of possible key enzymes for CD60a,b,c synthesis and degradation at the transcriptional level. Both, surface and cytoplasmic expression of CD60a and CD60c was highest in tonsillar T cells. In thymocytes, CD60c outweighs the other CD60 va... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102677 Wed, 03 Aug 2011 23:00:00 +0100 5102677 http://www.medworm.com/index.php?rid=5102676&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1147%3Frss%3D1 N-Glycosylation is normally a co-translational process that occurs as soon as a nascent and unfolded polypeptide chain has emerged ~12 residues into the lumen of the endoplasmic reticulum (ER). Here, we describe the efficient utilization of an N-glycosylation site engineered within the luminal extreme C-terminal residues of distinct integral membrane glycoproteins, a native ER resident protein and an engineered secreted protein. This N-glycan addition required that the acceptor asparagine within an Asn-Trp-Ser sequon be located at least four residues away from the C-terminus of the polypeptide and, in the case of membrane proteins, at least 13 residues away from the lumenal side of the transmembrane segment. Pulse-chase assays revealed that the natural N-glycans of the proteins studied wer... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102676 Wed, 03 Aug 2011 23:00:00 +0100 5102676 http://www.medworm.com/index.php?rid=5102675&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1140%3Frss%3D1 Among the 21 O-polysaccharide (OPS) O-antigen-based serotypes described for Yersinia pseudotuberculosis, those of O:6 and O:7 are unusual in that both contain colitose (4-keto-3,6-dideoxy-d-mannose or 4-keto-3,6-dideoxy-l-xylo-hexose), which has not otherwise been reported for this species, and the O:6 OPS also contains yersiniose A (4-C[(R)-1-hydroxyethyl]-3,6-dideoxy-d-xylo-hexose), another unusual dideoxyhexose sugar. In Y. pseudotuberculosis, the genes for OPS synthesis generally cluster together between the hemH and gsk loci. Here, we present the sequences of the OPS gene clusters of Y. pseudotuberculosis O:6 and O:7, and the location of the genes required for synthesis of these OPSs, except that there is still ambiguity regarding allocation of some of the glycosyltransferase function... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102675 Wed, 03 Aug 2011 23:00:00 +0100 5102675 http://www.medworm.com/index.php?rid=5102674&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1131%3Frss%3D1 The O-specific polysaccharide (OPS) is a variable constituent of the lipopolysaccharide of Gram-negative bacteria. The polymorphic nature of OPSs within a species is usually first defined serologically, and the current serotyping scheme for Yersinia pseudotuberculosis consists of 21 O serotypes of which 15 have been characterized genetically and structurally. Here, we present the structure and DNA sequence of Y. pseudotuberculosis O:10 OPS. The O unit consists of one residue each of d-galactopyranose, N-acetyl-d-galactosamine (2-amino-2-deoxy-d-galactopyranose) and d-glucopyranose in the backbone, with two colitose (3,6-dideoxy-l-xylo-hexopyranose) side-branch residues. This structure is very similar to that shared by Escherichia coli O111 and Salmonella enterica O35. The gene cluster sequ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102674 Wed, 03 Aug 2011 23:00:00 +0100 5102674 http://www.medworm.com/index.php?rid=5102673&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1125%3Frss%3D1 The expression of the epitopes recognized by the monoclonal antibodies Tra-1-60 and Tra-1-81 is routinely used to assess the pluripotency status of human embryonic stem cells (hESCs) and induced pluripotent stem (iPS) cells. Although it is known that the epitopes recognized by Tra-1-60 and Tra-1-81 are carbohydrates, the exact molecular identity of these epitopes has been unclear. Glycan array analysis with more than 500 oligosaccharide structures revealed specific binding of Tra-1-60 and Tra-1-81 to two molecules containing terminal type 1 lactosamine: Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAc and Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAcβ1-6(Galβ1-3GlcNAcβ1-3)Galβ1-4Glc. The type 1 disaccharide in itself was not sufficient for binding, indicating that the comp... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102673 Wed, 03 Aug 2011 23:00:00 +0100 5102673 http://www.medworm.com/index.php?rid=5102672&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1121%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102672 Wed, 03 Aug 2011 23:00:00 +0100 5102672 http://www.medworm.com/index.php?rid=5102671&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1119%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102671 Wed, 03 Aug 2011 23:00:00 +0100 5102671 http://www.medworm.com/index.php?rid=5102670&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2F1117%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102670 Wed, 03 Aug 2011 23:00:00 +0100 5102670 http://www.medworm.com/index.php?rid=5102669&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102669 Wed, 03 Aug 2011 23:00:00 +0100 5102669 http://www.medworm.com/index.php?rid=5102668&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102668 Wed, 03 Aug 2011 23:00:00 +0100 5102668 http://www.medworm.com/index.php?rid=5102667&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F9%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5102667 Wed, 03 Aug 2011 23:00:00 +0100 5102667 http://www.medworm.com/index.php?rid=5006205&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1108%3Frss%3D1 Starch-branching enzyme catalyzes the cleavage of α-1, 4-linkages and the subsequent transfer of α-1,4 glucan to form an α-1,6 branch point in amylopectin. Sequence analysis of the rice-branching enzyme I (BEI) indicated a modular structure in which the central α-amylase domain is flanked on each side by the N-terminal carbohydrate-binding module 48 and the α-amylase C-domain. We determined the crystal structure of BEI at a resolution of 1.9 Å by molecular replacement using the Escherichia coli glycogen BE as a search model. Despite three modular structures, BEI is roughly ellipsoidal in shape with two globular domains that form a prominent groove which is proposed to serve as the α-polyglucan-binding site. Amino acid residues Asp344 and Glu39... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006205 Tue, 05 Jul 2011 23:00:00 +0100 5006205 http://www.medworm.com/index.php?rid=5006204&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1097%3Frss%3D1 The Tn antigen (GalNAc α-O-Ser/Thr) is heterogeneously synthesized by a variety of tumors and contains an epitope defined by lectins and antibodies as a cluster of αGalNAc carbohydrates synthesized within a peptide sequence, which is rich in serine and/or threonine. The Tn antigen has been utilized as a target in vaccine experiments and also used as a biomarker for prognosis of different cancer forms. In this paper, we present a new monoclonal antibody, GOD3-2C4, with the clear hallmarks of an anti-Tn antibody. It was generated through somatic cell hybridization after immunization of a mouse with a tumor cell line and a Tn carrying mucin. The antibody recognizes synthetic Tn antigen and binds breast, colon, lung, ovarian and pancreas cancer. The GOD3-2C4 antibody has antibody-d... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006204 Tue, 05 Jul 2011 23:00:00 +0100 5006204 http://www.medworm.com/index.php?rid=5006203&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1087%3Frss%3D1 We report here for the first time a detailed study of how hemi-glycosylation affects the stability and functional activities of an IgG1 antibody, mAb-X, in comparison to its fully glycosylated counterpart. Our results show that hemi-glycosylation does not impact Fab-mediated antigen binding, nor does it impact neonatal Fc receptor binding. Hemi-glycosylated mAb-X has slightly decreased thermal stability in the CH2 domain and a moderate decrease (~20%) in C1q binding. More importantly, the hemi-glycosylated form shows significantly decreased binding affinities toward all Fc gamma receptors (FcRs) including the high-affinity FcRI, and the low-affinity FcRIIA, FcRIIB, FcRIIIA and FcRIIIB. The decreased binding affinities to FcRs result in a 3.5-fold decrease in antibody-dependent cell cytotox... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006203 Tue, 05 Jul 2011 23:00:00 +0100 5006203 http://www.medworm.com/index.php?rid=5006202&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1071%3Frss%3D1 In conclusion, PSGL-1/mIgG2b expressed in P. pastoris carried O-glycans mainly comprised of α-linked mannoses and with up to nine residues. It bound mannose-specific receptors with high apparent affinity and may become a potent targeting molecule for these receptors in vivo. (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006202 Tue, 05 Jul 2011 23:00:00 +0100 5006202 http://www.medworm.com/index.php?rid=5006201&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1060%3Frss%3D1 Altered protein glycosylation compared with the disease-free state is a universal feature of cancer cells. It has long been established that distinct glycan structures are associated with specific forms of cancer, but far less is known about the complete array of glycans associated with certain tumors. The cancer glycome has great potential as a source of biomarkers, but progress in this field has been hindered by a lack of available techniques for the elucidation of disease-associated glycosylation. In the present study, lectin microarrays consisting of 45 lectins with different binding preferences covering N- and O-linked glycans were coupled with evanescent-field activated fluorescent detection in the glycomic analysis of primary breast tumors and the serum and urine of patients with me... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006201 Tue, 05 Jul 2011 23:00:00 +0100 5006201 http://www.medworm.com/index.php?rid=5006200&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1049%3Frss%3D1 The structure of the antigen-binding fragment from the monoclonal antibody S64-4 in complex with a pentasaccharide bisphosphate fragment from chlamydial lipopolysaccharide has been determined by x-ray diffraction to 2.6 Å resolution. Like the well-characterized antibody S25-2, S64-4 displays a pocket formed by the residues of germline sequence corresponding to the heavy and light chain V gene segments that binds the terminal Kdo residue of the antigen; however, although S64-4 shares the same heavy chain V gene segment as S25-2, it has a different light chain V gene segment. The new light chain V gene segment codes for a combining site that displays greater affinity, different specificity, and allows a novel antigen conformation that brings a greater number of antigen residues in... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006200 Tue, 05 Jul 2011 23:00:00 +0100 5006200 http://www.medworm.com/index.php?rid=5006199&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1038%3Frss%3D1 Siglecs (Sialic acid-binding Immunoglobulin Superfamily Lectins) are cell surface signaling receptors of the I-type lectin group that recognize sialic acid-bearing glycans. CD33-related-Siglecs are a subset with expression primarily in cells of hematopoietic origin and functional relevance to immune reactions. Earlier we reported a human-specific gene conversion event that markedly changed the coding region for the extracellular domain of Siglec-11, associated with human-specific expression in microglia (Hayakawa T, Angata T, Lewis AL, Mikkelsen TS, Varki NM, Varki A. 2005. A human-specific gene in microglia. Science. 309:1693). Analyzing human gene microarrays to define new patterns of expression, we observed high levels of SIGLEC11 transcript in the ovary and adrenal cortex. Thus, we exa... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006199 Tue, 05 Jul 2011 23:00:00 +0100 5006199 http://www.medworm.com/index.php?rid=5006198&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1029%3Frss%3D1 A number of glycosaminoglycan (GAG) species related to heparin, dermatan sulfate (DeS) and chondroitin sulfate were tested for their ability to interfere with the physiological expression and/or pathological overexpression of the TGF-β1 gene. The influence of the molecular weight, molecular weight distribution, degree of sulfation and location of the sulfate groups was examined in an attempt to unveil fine relationships between structure and activity. The nature of the polysaccharide plays a major part, heparins proving able to inhibit both basal and stimulated TGF-β1 gene expression, DeSs being essentially inactive and chondroitin sulfates only inhibiting stimulated TGF-β1 gene expression. Within this frame, the particular physical and chemical properties of some GAGs appea... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006198 Tue, 05 Jul 2011 23:00:00 +0100 5006198 http://www.medworm.com/index.php?rid=5006197&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1019%3Frss%3D1 Therapeutic glycoproteins with exposed galactose (Gal) residues are cleared rapidly from the bloodstream by asialoglycoprotein receptors in hepatocytes. Various approaches have been used to increase the content of sialic acid, which occupies terminal sites of N- or O-linked glycans and thereby increases the half-life of therapeutic glycoproteins. We enhanced sialylation of human erythropoietin (EPO) by genetic engineering of the sialylation pathway in Chinese hamster ovary (CHO) cells. The enzyme GNE (uridine diphosphate-N-acetyl glucosamine 2-epimerase)/MNK (N-acetyl mannosamine kinase), which plays a key role in the initial two steps of sialic acid biosynthesis, is regulated by cytidine monophosphate (CMP)-sialic acid through a feedback mechanism. Since sialuria patient cells fail in reg... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006197 Tue, 05 Jul 2011 23:00:00 +0100 5006197 http://www.medworm.com/index.php?rid=5006196&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1010%3Frss%3D1 In this study, we investigated the influence of polysialylation on cell migration. PSA consistently promoted cell migration on different extracellular matrices (ECMs) but differentially affected cell adhesion. All of these actions were reversed by endo-N-acetylneuraminidase treatment, and PSA-driven migration was inhibited by the specific fibroblast growth factor receptor (FGFR) inhibitor Su5402. Consistent with this latter observation, PSA-stimulated migration on different ECMs was paralleled by activation of the FGFR and its downstream signaling components, PLC-, focal adhesion kinase and extracellular signal-regulated kinase 1/2. In contrast, the pattern of p59fyn activation correlated with differential adhesion to different ECMs. Collectively, these results indicate that PSA-conjugated... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006196 Tue, 05 Jul 2011 23:00:00 +0100 5006196 http://www.medworm.com/index.php?rid=5006195&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F1000%3Frss%3D1 A novel lectin has been isolated from the fruiting bodies of the common edible mushroom Boletus edulis (king bolete, penny bun, porcino or cep) by affinity chromatography on a chitin column. We propose for the lectin the name BEL (B. edulis lectin). BEL inhibits selectively the proliferation of several malignant cell lines and binds the neoplastic cell-specific T-antigen disaccharide, Galβ1-3GalNAc. The lectin was structurally characterized: the molecule is a homotetramer and the 142-amino acid sequence of the chains was determined. The protein belongs to the saline-soluble family of mushroom fruiting body-specific lectins. BEL was also crystallized and its three-dimensional structure was determined by X-ray diffraction to 1.15 Å resolution. The structure is similar to that... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006195 Tue, 05 Jul 2011 23:00:00 +0100 5006195 http://www.medworm.com/index.php?rid=5006194&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F994%3Frss%3D1 The vesicular transport pathway in plant cells is often used for higher accumulation of recombinant proteins. In the endoplasmic reticulum, which acts as a gateway to the vesicular transport pathway, N-glycosylation occurs on specific Asn residues. This N-glycosylation in recombinant proteins must be carefully regulated as it can impact their enzymatic activity, half lives in serum when injected, structural stability, etc. In eukaryotic cells, including plant cells, N-glycans were found to be attached to Asn residues in Asn-X-Ser/Thr (X != Pro) sequences. However, recently, N-glycosylations at noncanonical Asn-X-Cys sequences have been found in mammals and yeast. Our laboratory has discovered that N-glycans are attached to Asn residues at Asn-Thr-Cys sequences of double-repeated ... Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006194 Tue, 05 Jul 2011 23:00:00 +0100 5006194 http://www.medworm.com/index.php?rid=5006193&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F988%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006193 Tue, 05 Jul 2011 23:00:00 +0100 5006193 http://www.medworm.com/index.php?rid=5006192&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F987%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006192 Tue, 05 Jul 2011 23:00:00 +0100 5006192 http://www.medworm.com/index.php?rid=5006191&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2F985%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006191 Tue, 05 Jul 2011 23:00:00 +0100 5006191 http://www.medworm.com/index.php?rid=5006190&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2FNP-b%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006190 Tue, 05 Jul 2011 23:00:00 +0100 5006190 http://www.medworm.com/index.php?rid=5006189&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2FNP-a%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006189 Tue, 05 Jul 2011 23:00:00 +0100 5006189 http://www.medworm.com/index.php?rid=5006188&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F8%2FNP%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=5006188 Tue, 05 Jul 2011 23:00:00 +0100 5006188 http://www.medworm.com/index.php?rid=4910246&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F973%3Frss%3D1 Glycan chains that terminate in sialic acid (Neu5Ac) are frequently the receptors targeted by pathogens for initial adhesion. Carbohydrate-binding proteins (lectins) with specificity for Neu5Ac are particularly useful in the detection and isolation of sialylated glycoconjugates, such as those associated with pathogen adhesion as well as those characteristic of several diseases including cancer. Structural studies of lectins are essential in order to understand the origin of their specificity, which is particularly important when employing such reagents as diagnostic tools. Here, we report a crystallographic and molecular dynamics (MD) analysis of a lectin from Polyporus squamosus (PSL) that is specific for glycans terminating with the sequence Neu5Acα2-6Galβ. Because of its impo... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910246 Tue, 07 Jun 2011 23:00:00 +0100 4910246 http://www.medworm.com/index.php?rid=4910245&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F960%3Frss%3D1 Chondroitin sulfate (CS)/dermatan sulfate (DS) is a group of sulfated polymers, which play an essential role in various biological phenomena. In the kidney, they are present in small but significant amounts. Studies on their structure–function relationship in the kidney and their changes during diabetic conditions have not been rigorously looked into, which is the focus of this paper. The CS/DS content decreased significantly (14%) during diabetic conditions. This was accompanied by a decrease in the CS/heparan sulfate ratio. Disaccharide composition analysis revealed fine structural changes especially with respect to the E unit [glucuronic acid β1-3 N-acetyl d-galactosamine (4,6-O-sulfate)] and the degree of sulfation. The mRNA expression levels of major enzymes involved in the... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910245 Tue, 07 Jun 2011 23:00:00 +0100 4910245 http://www.medworm.com/index.php?rid=4910244&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F949%3Frss%3D1 Glycan structures attached to the CH2 domain of the Fc region of immunoglobulin G (IgG) are essential for specific effector functions but their role in modulating clearance is less clear. Clearance is of obvious importance for therapeutic monoclonal antibodies (Mabs) as it directly impacts efficacy. Here, we study the impact of Fc glycan structure on the clearance of four therapeutic human IgGs (one IgG1 and three IgG2s) in humans. The therapeutic IgGs were affinity purified from serum samples from human pharmacokinetic studies, and changes to the glycan profile over time were determined by peptide mapping employing high-resolution mass spectrometry. Relative levels of high-mannose 5 (M5) glycan decreased as a function of circulation time, whereas other glycans remained constant. These res... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910244 Tue, 07 Jun 2011 23:00:00 +0100 4910244 http://www.medworm.com/index.php?rid=4910243&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F934%3Frss%3D1 In this study, SCWPs from three strains of B. cereus causing severe or fatal pneumonia (G9241, 03BB87 and 03BB102) were isolated and subjected to structural analysis and their structures were compared to SCWPs from B. anthracis. Complete structural analysis was performed for the B. cereus G9241 SCWP using NMR spectroscopy, mass spectrometry and derivatization methods. The analyses show that SCWPs from B. cereus G9241 has a glycosyl backbone identical to that of B. anthracis SCWP, consisting of multiple trisaccharide repeats of: ->6)-α-d-GlcpNAc-(1 -> 4)-β-d-ManpNAc-(1 -> 4)-β-d-GlcpNAc-(1->. Both the B. anthracis and pathogenic B. cereus SCWPs are highly substituted at all GlcNAc residues with α- and β-Gal residues, however, only t... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910243 Tue, 07 Jun 2011 23:00:00 +0100 4910243 http://www.medworm.com/index.php?rid=4910242&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F925%3Frss%3D1 The legume species of Cymbosema roseum of Diocleinae subtribe produce at least two different seed lectins. The present study demonstrates that C. roseum lectin I (CRL I) binds with high affinity to the "core" trimannoside of N-linked oligosaccharides. Cymbosema roseum lectin II (CRL II), on the other hand, binds with high affinity to the blood group H trisaccharide (Fucα1,2Galα1-4GlcNAc-). Thermodynamic and hemagglutination inhibition studies reveal the fine binding specificities of the two lectins. Data obtained with a complete set of monodeoxy analogs of the core trimannoside indicate that CRL I recognizes the 3-, 4- and 6-hydroxyl groups of the α(1,6) Man residue, the 3- and 4-hydroxyl group of the α(1,3) Man residue and the 2- and 4-hydroxyl groups of the centra... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910242 Tue, 07 Jun 2011 23:00:00 +0100 4910242 http://www.medworm.com/index.php?rid=4910241&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F914%3Frss%3D1 Glucose-6-phosphatase, an enzyme localized in the endoplasmic reticulum (ER), catalyzes the hydrolysis of glucose-6-phosphate (G6P) to glucose and inorganic phosphate. In humans, there are three differentially expressed glucose-6-phosphatase catabolic genes (G6PC1–3). Recently, it has been shown that mutations in the G6PC3 gene result in a syndrome associating congenital neutropenia and various organ malformations. The enzymatic function of G6PC3 is dependent on G6P transport into the ER, mediated by G6P translocase (G6PT). Mutations in the gene encoding G6PT result in glycogen storage disease type-1b (GSD-1b). Interestingly, GSD-1b patients exhibit a similar neutrophil dysfunction to that observed in G6PC3-deficient patients. To better understand the causes of neutrophil dysfunction... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910241 Tue, 07 Jun 2011 23:00:00 +0100 4910241 http://www.medworm.com/index.php?rid=4910240&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F903%3Frss%3D1 We describe the first biochemical characterization of the gumI gene product, an essential protein for xanthan polysaccharide synthesis. Cellular fractionation experiments reveal the presence of a protein associated with the membrane fraction, even in the absence of the other proteins responsible for the synthesis of glycolipid intermediates and the proteins involved in the polymerization and transport of the xanthan chains. By alkaline buffer extraction and detergent phase partitioning, GumI was categorized as a monotopic membrane protein. GumI was overexpressed in Escherichia coli, solubilized and purified in an active and stable form using a simple and reproducible two-step procedure. The purified recombinant GumI is a nonprocessive β-mannosyltransferase that uses GDP-Man as a donor... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910240 Tue, 07 Jun 2011 23:00:00 +0100 4910240 http://www.medworm.com/index.php?rid=4910239&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F895%3Frss%3D1 Cell-surface carbohydrates are known to participate in many important physiological and pathological activities by interacting with their corresponding proteins or receptors. Although several methods have been developed for studying carbohydrate–protein interactions, one major problem originates from the weak bindings of carbohydrates/proteins that are often lost during repeating wash steps. Herein, we established a homogeneous solution carbohydrate array in which polyacrylamide-based glycans are used for offering a multivalent environment. The method requires no wash step and can be carried out in a high-throughput manner. We characterized the carbohydrate-binding specificities of 11 lectins and 7 antibodies, the majority of which displayed the binding patterns in consistence with p... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910239 Tue, 07 Jun 2011 23:00:00 +0100 4910239 http://www.medworm.com/index.php?rid=4910238&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F877%3Frss%3D1 Differences in the fertilization behavior of Xenopus borealis from X. laevis and X. tropicalis suggest differences in the glycosylation of the egg jellies. To test this assumption, O-linked glycans were chemically released from the egg jelly coat glycoproteins of X. borealis. Over 50 major neutral glycans were observed, and no anionic glycans were detected from the released O-glycan pool. Preliminary structures of ~30 neutral oligosaccharides were determined using matrix-assisted laser desorption/ionization (MALDI) infrared multiphoton dissociation tandem mass spectrometry (MS). The mass fingerprint of a group of peaks for the core-2 structure of O-glycans was conserved in the tandem mass spectra and was instrumental in rapid and efficient structure determination. Among the 29 O-glycans, 2... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910238 Tue, 07 Jun 2011 23:00:00 +0100 4910238 http://www.medworm.com/index.php?rid=4910237&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F864%3Frss%3D1 Initially described by Jaeken et al. in 1980, congenital disorders of glycosylation (CDG) is a rapidly expanding group of human multisystemic disorders. To date, many CDG patients have been identified with deficiencies in the conserved oligomeric Golgi (COG) complex which is a complex involved in the vesicular intra-Golgi retrograde trafficking. Composed of eight subunits that are organized in two lobes, COG subunit deficiencies have been associated with Golgi glycosylation abnormalities. Analysis of the total serum N-glycans of COG-deficient CDG patients demonstrated an overall decrease in terminal sialylation and galactosylation. According to the mutated COG subunits, differences in late Golgi glycosylation were observed and led us to address the question of an independent role and requi... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910237 Tue, 07 Jun 2011 23:00:00 +0100 4910237 http://www.medworm.com/index.php?rid=4910236&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F853%3Frss%3D1 Protein glycosylation is one of the major biosynthetic functions occurring in the endoplasmic reticulum and Golgi compartments. It requires an amazing number of enzymes, chaperones, lectins and transporters whose actions delicately secure the fidelity of glycan structures. Over the past 30 years, glycobiologists hammered that glycan structures are not mere decorative elements but serve crucial cellular functions. This becomes dramatically illustrated by a group of mostly severe, inherited human disorders named congenital disorders of glycosylation (CDG). To date, many types of CDG have been defined genetically and most of the time the defects impair the biosynthesis, transfer and remodeling of N-glycans. Recently, the identification of the several types of CDG caused by deficiencies in the... Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910236 Tue, 07 Jun 2011 23:00:00 +0100 4910236 http://www.medworm.com/index.php?rid=4910235&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F852%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910235 Tue, 07 Jun 2011 23:00:00 +0100 4910235 http://www.medworm.com/index.php?rid=4910234&cid=s_32007_62_f&fid=32007&url=http%3A%2F%2Fglycob.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F21%2F7%2F849%3Frss%3D1 (Source: Glycobiology) Glycobiology journals http://www.medworm.com/rss/comments.php?id=4910234 Tue, 07 Jun 2011 23:00:00 +0100 4910234