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247 records returned

CSD mRNA expression in rat testis and the effect of taurine on testosterone secretion.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In the present study, the cysteine sulfinate decarboxylase (CSD) mRNA expression was detected in rat testis by RT-PCR. The results showed that CSD mRNA was expressed in rat testis, and the putative encoded-amino acid sequence was exactly the same as that in rat liver which was already known. At the same time, the effects of taurine on testosterone secretion were investigated both in vivo and in vitro. In vivo, taurine were administered to male rats by tap water. The results showed that taurine obviously stimulated the secretion of FSH, LH and testosterone in serum, but showed no significant effect on the secretion of e...
Source: Amino Acids - November 18, 2009 Category: Biochemistry Authors: Yang J, Wu G, Feng Y, Sun C, Lin S, Hu J Tags: Amino Acids Source Type: journals

Synthesis of orthogonally protected L: -threo-beta-ethoxyasparagine.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Orthogonally protected L: -threo-beta-ethoxyasparagine (Fmoc-EtOAsn(Trt)-OH, 1) was synthesized from diethyl (2S,3S)-2-azido-3-hydroxysuccinate 2 in eight steps as a building block for solid-phase peptide synthesis. The starting material is easily available in multi-gram scale from D: -diethyltartrate. The transformation steps reported here are robust and scalable. Thus, a significant amount of 1 (1.8 g) was obtained in 21% overall yield. The synthesis reported is also expected to be useful for the preparation of other O-substituted L: -threo-beta-hydroxyasparagine derivatives. PMID: 19921395 [PubMed - as supplied ...
Source: Amino Acids - November 17, 2009 Category: Biochemistry Authors: Spengler J, Pelay M, Tulla-Puche J, Albericio F Tags: Amino Acids Source Type: journals

The effects of a low protein diet on amino acids and enzymes in the serine synthesis pathway in mice.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, the levels of amino acids and enzymes in the L: -serine biosynthetic pathway were examined in the forebrain, cerebellum, liver, and kidney after the exposure of mice to protein-restricted diets. The levels of L: -serine, D: -serine, and L: -serine-O-phosphate were quantified by HPLC and quantitative Western blotting was used to measure changes in protein levels of five enzymes in the pathway. The L: -serine biosynthetic enzyme phosphoserine phosphatase was strongly upregulated, while the serine degradative enzymes serine racemase and serine dehydratase were downregulated in the livers and kidneys of mice fed...
Source: Amino Acids - November 17, 2009 Category: Biochemistry Authors: Antflick JE, Baker GB, Hampson DR Tags: Amino Acids Source Type: journals

Stereoselective introduction of two chiral centers by a single diketoreductase: an efficient biocatalytic route for the synthesis of statin side chains.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Statins, including atorvastatin (Lipitor((R))), are the top-selling drugs in the world. The biocatalytic production of chiral side chains of statin drugs is of great interest to academia and industry. Stereoselective double reduction of a beta,delta-diketo ester catalyzed by a diketoreductase offers a simple and efficient route for the preparation of statin side chains. Comparison of different cofactor regeneration systems resulted in an easy and cost-effective process for this enzymatic reduction. PMID: 19916068 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - November 16, 2009 Category: Biochemistry Authors: Wu X, Wang L, Wang S, Chen Y Tags: Amino Acids Source Type: journals

Taurine inhibits osteoclastogenesis through the taurine transporter.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Several studies have suggested a direct link between taurine and bone homeostasis. However, the mechanisms of taurine on the regulation of bone metabolism have not been elucidated. Using a coculture of osteoblasts and bone marrow cells as a model for the study of osteoclastogenesis, RANKL-stimulated RAW264.7 cells and M-CSF- and RANKL-induced bone marrow macrophages were investigated to elucidate the possible roles of taurine in osteoclastogenesis. Taurine inhibited osteoclastogenesis in the coculture of osteoblasts and bone marrow cells, but did not influence the expression of OPG and RANKL in osteoblasts. The taurine...
Source: Amino Acids - November 14, 2009 Category: Biochemistry Authors: Yuan LQ, Liu W, Cui RR, Wang D, Meng JC, Xie H, Wu XP, Zhou HD, Lu Y, Liao EY Tags: Amino Acids Source Type: journals

Relevance of allosteric conformations and homocarnosine concentration on carnosinase activity.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Activity of carnosinase (CN1), the only dipeptidase with substrate specificity for carnosine or homocarnosine, varies greatly between individuals but increases clearly and significantly with age. Surprisingly, the lower CN1 activity in children is not reflected by differences in CN1 protein concentrations. CN1 is present in different allosteric conformations in children and adults since all sera obtained from children but not from adults were positive in ELISA and addition of DTT to the latter sera increased OD450 values. There was no quantitative difference in the amount of monomeric CN1 between children and adults. F...
Source: Amino Acids - November 14, 2009 Category: Biochemistry Authors: Peters V, Kebbewar M, Jansen EW, Jakobs C, Riedl E, Koeppel H, Frey D, Adelmann K, Klingbeil K, Mack M, Hoffmann GF, Janssen B, Zschocke J, Yard BA Tags: Amino Acids Source Type: journals

2-Oxo-2H-benzo[h]benzopyran as a new light sensitive protecting group for neurotransmitter amino acids.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Aiming at the development of new benzopyran-based photocleavable protecting groups, novel chloromethylated and hydroxymethylated 2-oxo-2H-benzo[h]benzopyran derivatives bearing a methoxy substituent were designed and used in the synthesis of a series of fluorescent bioconjugates, by linking through an ester or urethane bond to several model neurotransmitter amino acids (glycine, alanine, beta-alanine and gamma-aminobutyric acid, GABA). The resulting fluorescent bioconjugates with emission in the visible range and high fluorescent quantum yields, were subjected to photocleavage reaction in methanol/HEPES buffer (80:20) ...
Source: Amino Acids - November 12, 2009 Category: Biochemistry Authors: Soares AM, Costa SP, Gonçalves MS Tags: Amino Acids Source Type: journals

Prediction of mitochondrial proteins of malaria parasite using split amino acid composition and PSSM profile.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we describe a method for predicting mitochondrial proteins of malaria parasite using machine-learning technique. All models were trained and tested on 175 proteins (40 mitochondrial and 135 non-mitochondrial proteins) and evaluated using five-fold cross validation. We developed a Support Vector Machine (SVM) model for predicting mitochondrial proteins of P. falciparum, using amino acids and dipeptides composition and achieved maximum MCC 0.38 and 0.51, respectively. In this study, split amino acid composition (SAAC) is used where composition of N-termini, C-termini, and rest of protein is computed separately...
Source: Amino Acids - November 12, 2009 Category: Biochemistry Authors: Verma R, Varshney GC, Raghava GP Tags: Amino Acids Source Type: journals

Metabolic stability of human parathyroid hormone peptide hPTH (1-34) in rat tissue homogenates: kinetics and products of proteolytic degradation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The present study aim to investigate the metabolic stability and degradation of cleavage sites of human parathyroid hormone peptide, hPTH (1-34), in rat tissue homogenate, and to identify the types of proteases involved in hPTH (1-34) processing degradation. The stability of hPTH (1-34) in rat kidney, lung and liver homogenates was evaluated by LC-ESI-MS, and the structures of the major degradation products were identified by MALDI-TOF MS and LC-ESI-MS/MS. The ability of protease inhibitors to inhibit hPTH (1-34) degradation was used to identify the class of proteases involved in the metabolism of hPTH (1-34). hPTH (1-...
Source: Amino Acids - November 6, 2009 Category: Biochemistry Authors: Liao S, Qie JK, Xue M, Zhang ZQ, Liu KL, Ruan JX Tags: Amino Acids Source Type: journals

Involvement of individual hippocampal signaling protein levels in spatial memory formation is strain-dependent.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Although a series of signaling cascades involved in spatial memory have been identified, their link to spatial memory and strain-dependent expression has not been reported so far. Hippocampal levels of the abovementioned signaling proteins were determined in laboratory inbred strain C57BL/6J, the wild-derived inbred strain PWD/PhJ and the wild caught mouse Apodemus sylvaticus (AS) by immunoblotting. The resulting hippocampal protein levels were correlated with results from MWM. Hippocampal signaling protein (hSP) levels were tested also in yoked controls. Within-strain comparison between trained and yoked controls reve...
Source: Amino Acids - November 5, 2009 Category: Biochemistry Authors: Patil SS, Schlick F, Höger H, Lubec G Tags: Amino Acids Source Type: journals

Evidence for the involvement of D: -aspartic acid in learning and memory of rat.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, this study provides corroborating evidence that D: -aspartic acid plays an important role in the modulation of learning and memory. PMID: 19890700 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - November 5, 2009 Category: Biochemistry Authors: Topo E, Soricelli A, Di Maio A, D'Aniello E, Di Fiore MM, D'Aniello A Tags: Amino Acids Source Type: journals

Subcellular localization of the interaction between the human immunodeficiency virus transactivator Tat and the nucleosome assembly protein 1.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The histone chaperone nucleosome assembly protein, hNAP-1, is a host cofactor for the activity of the human immunodeficiency virus type 1 (HIV-1) transactivator Tat. The interaction between these two proteins has been shown to be important for Tat-mediated transcriptional activation and for efficient viral infection. Visualization of HIV-1 transcription and fluorescence resonance energy transfer experiments performed in this work demonstrate that hNAP-1 is not recruited to the site of Tat activity but the two proteins interact at the nuclear rim. These data are consistent with a mechanism that requires hNAP-1 for the t...
Source: Amino Acids - November 4, 2009 Category: Biochemistry Authors: De Marco A, Dans PD, Knezevich A, Maiuri P, Pantano S, Marcello A Tags: Amino Acids Source Type: journals

Isoform-specific determinants in the HP1 binding to histone 3: insights from molecular simulations.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Despite the significant improvements in anti HIV-1 treatment, AIDS remains a lifelong disease due to the impossibility to eradicate the viral reservoir established upon integration of the viral genome. Controlling the epigenetic block imposed by the host cell machinery to the viral transcription may represent a therapeutic alternative to purge the viral reservoir, offering a way to eradicate the infection. Heterochromatin protein 1 (HP1) has been reported to actively participate in the silencing of HIV-1 integrated genome by binding to histone 3 (H3) tail. This interaction is mediated by the Chromodomain of HP1. Nevert...
Source: Amino Acids - November 4, 2009 Category: Biochemistry Authors: Machado MR, Dans PD, Pantano S Tags: Amino Acids Source Type: journals

Synthesis and biological activity of oxytocin analogues containing unnatural amino acids in position 9: structure activity study.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We report the solid phase synthesis and some pharmacological properties of 24 oxytocin (OT) analogues. Basic modifications at position 9 (introduction of L: - or D: -beta-(2-thienyl)-alanine [L- or D-Thi], or L: - or D: -3-Pyridylalanine [L: - or D: -3-Pal]) were combined with D: -tyrosine(OEthyl) [D: -Tyr(Et)] or D: -1-naphthylalanine [D: -1-Nal] in position 2 and beta-mercaptopropionic acid (Mpa) in position 1 modifications in altogether 14 analogues. Additionally, 8 analogues having alpha-aminoisobutyric acid [Aib] or D: -1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (D: -Tic) or diethylglycine (Deg) in position 9 an...
Source: Amino Acids - November 3, 2009 Category: Biochemistry Authors: Magafa V, Borovičková L, Slaninová J, Cordopatis P Tags: Amino Acids Source Type: journals

Enriching the viral-host interactomes with interactions mediated by SH3 domains.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Protein-protein interactions play an essential role in the regulation of most cellular processes. The process of viral infection is no exception and many viral pathogenic strategies involve targeting and perturbing host-protein interactions. The characterization of the host protein subnetworks disturbed by invading viruses is a major goal of viral research and may contribute to reveal fundamental biological mechanisms and to identify new therapeutic strategies. To assist in this approach, we have developed a database, VirusMINT, which stores in a structured format most of the published interactions between viral and ho...
Source: Amino Acids - November 2, 2009 Category: Biochemistry Authors: Carducci M, Licata L, Peluso D, Castagnoli L, Cesareni G Tags: Amino Acids Source Type: journals

Distinct anabolic signalling responses to amino acids in C2C12 skeletal muscle cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The essential amino acids (EAA) activate anabolic signalling through mechanisms, which are unclear in detail but include increased signalling through the mammalian target of rapamycin complex 1 (mTORC1). Of all the EAA, the branched chain amino acid (BCAA) leucine has been suggested as the most potent in stimulating protein synthesis, although there have been no studies investigating the effects of each EAA on anabolic signalling pathways. We therefore undertook a systematic analysis of the effect of each EAA on mTORC1 signalling in C2C12 myotubes whereby cells were serum (4 h) and amino acid (1 h) starved before stimu...
Source: Amino Acids - November 1, 2009 Category: Biochemistry Authors: Atherton PJ, Smith K, Etheridge T, Rankin D, Rennie MJ Tags: Amino Acids Source Type: journals

Induction of type I interferon by RNA viruses: cellular receptors and their substrates.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Virus recognition and induction of interferon (IFN) are critical components of the innate immune system. The Toll-like receptor (TLR) and RIG-I-like receptor families have been characterized as key players in RNA virus detection. Signaling cascades initiated by these receptors are crucial for establishment of an IFN signaling mediated antiviral state in infected and neighboring cells and containment of virus replication as well as initiation of the adaptive immune response. In this review, we focus on the diverse and overlapping functions of these receptors, their physiological importance, and respective viral inducers...
Source: Amino Acids - November 1, 2009 Category: Biochemistry Authors: Baum A, García-Sastre A Tags: Amino Acids Source Type: journals

Molecular mechanisms of flavivirus membrane fusion.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Flaviviruses comprise a number of important human pathogens including yellow fever, dengue, West Nile, Japanese encephalitis and tick-borne encephalitis viruses. They are small enveloped viruses that enter cells by receptor-mediated endocytosis and release their nucleocapsid into the cytoplasm by fusing their membrane with the endosomal membrane. The fusion event is triggered by the acidic pH in the endosome and is mediated by the major envelope protein E. Based on the atomic structures of the pre- and post-fusion conformations of E, a fusion model has been proposed that includes several steps leading from the metastab...
Source: Amino Acids - November 1, 2009 Category: Biochemistry Authors: Stiasny K, Fritz R, Pangerl K, Heinz FX Tags: Amino Acids Source Type: journals

Free amino acid production during tomato fruit ripening: a focus on L: -glutamate.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In tomato, free amino acids increase dramatically during fruit ripening and their abundance changed differentially. More evident is L: -glutamate which gives the characteristic "umami" flavor. Glutamate is the principal free amino acid of ripe fruits of cultivated varieties. In this paper, we examined the capacity of tomato fruits to process endogenous as well as exogenous polypeptides during the ripening transition, in order to analyze their contribution to the free amino acid pool. In addition, the activity of some enzymes involved in glutamate metabolism such as gamma-glutamyl transpeptidase (gamma-GTase), glutamate...
Source: Amino Acids - October 30, 2009 Category: Biochemistry Authors: Sorrequieta A, Ferraro G, Boggio SB, Valle EM Tags: Amino Acids Source Type: journals

Chronic hyperhomocysteinemia impairs vascular function in ovariectomized rat carotid arteries.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, our findings show that severe HHCy can promote an acute decrease in the endothelium-independent contractile responses of carotid arteries to adrenergic agonists. This effect was restored by nitric oxide synthase inhibitors, which further supports the involvement of nitric oxide in HHcy-derived vascular dysfunction. PMID: 19876715 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - October 30, 2009 Category: Biochemistry Authors: Celotto AC, Fukada SY, Laurindo FR, Haddad R, Eberlin MN, de Oliveira AM Tags: Amino Acids Source Type: journals

Icaritin induces growth inhibition and apoptosis of human prostatic smooth muscle cells in an estrogen receptor-independent manner.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Icaritin has selective estrogen receptor (ER) modulating activity. ERs are expressed in the prostate stroma, and estrogens have an important role in the pathology of benign prostatic hyperplasia (BPH). However, the impact of icaritin on BPH was not studied. Human prostatic smooth muscle cells (PSMCs) were treated with 0-100 muM icaritin, also using 10 muM ICI182780 as a specific ER antagonist. The effects on cell growth and apoptosis were determined by cell counting and sandwich-enzyme-immunoassay. Western blotting was employed to illustrate the possible mechanisms. Cell growth was strongly inhibited by icaritin, and t...
Source: Amino Acids - October 30, 2009 Category: Biochemistry Authors: Chen MF, Qi L, Li Y, Zu XB, Dai YQ, Zhang P Tags: Amino Acids Source Type: journals

Structural analysis of the complex between calmodulin and full-length myelin basic protein, an intrinsically disordered molecule.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Myelin basic protein (MBP) is present between the cytoplasmic leaflets of the compact myelin membrane in both the peripheral and central nervous systems, and characterized to be intrinsically disordered in solution. One of the best-characterized protein ligands for MBP is calmodulin (CaM), a highly acidic calcium sensor. We pulled down MBP from human brain white matter as the major calcium-dependent CaM-binding protein. We then used full-length brain MBP, and a peptide from rodent MBP, to structurally characterize the MBP-CaM complex in solution by small-angle X-ray scattering, NMR spectroscopy, synchrotron radiation c...
Source: Amino Acids - October 24, 2009 Category: Biochemistry Authors: Majava V, Wang C, Myllykoski M, Kangas SM, Kang SU, Hayashi N, Baumgärtel P, Heape AM, Lubec G, Kursula P Tags: Amino Acids Source Type: journals

Virus entry paradigms.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Viruses, despite being relatively simple in structure and composition, have evolved to exploit complex cellular processes for their replication in the host cell. After binding to their specific receptor on the cell surface, viruses (or viral genomes) have to enter cells to initiate a productive infection. Though the entry processes of many enveloped viruses is well understood, that of most non-enveloped viruses still remains unresolved. Recent studies have shown that compared to direct fusion at the plasma membrane, endocytosis is more often the preferred means of entry into the target cell. Receptor-mediated endocytic...
Source: Amino Acids - October 14, 2009 Category: Biochemistry Authors: Kalia M, Jameel S Tags: Amino Acids Source Type: journals

Daily quadratic trend in basal monocyte expressed HSP72 in healthy human subjects.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The inducible human stress protein heat shock protein 72 (HSP72) performs vital roles within the body at rest and during periods of stress. Recently it was shown over a 24 h period that basal HSP72 followed a diurnal variation. However, these results and previous literature demonstrate noticeable inter-subject variation in basal HSP72 expression. The notion of intra/inter-day variation in basal HSP72 expression has not been explored in detail. Basal monocyte expressed HSP72 was determined every 3 h, over a 9 h period in 12 healthy male subjects (20.2 +/- 1.9 years, 178.7 +/- 5.6 cm, 75.1 +/- 6.0 kg) within a temperatur...
Source: Amino Acids - October 8, 2009 Category: Biochemistry Authors: Taylor L, Midgley AW, Chrismas B, Madden LA, Vince RV, McNaughton LR Tags: Amino Acids Source Type: journals

Synthesis, spectroscopic studies and biological activity of a novel nucleopeptide with Moloney murine leukemia virus reverse transcriptase inhibitory activity.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this work, we report the synthesis of an alternate nucleo-alpha,epsilon-peptide based on L: -lysine moieties, an in vitro study of its biological activity, and spectroscopical binding studies between the novel nucleopeptide and Moloney murine leukemia virus reverse transcriptase as well as RNA. An alternate homothymine hexamer was synthesized by a straightforward solid phase route starting from commercial materials, purified by RP-HPLC and characterized by ESI-MS. The efficiency of the novel nucleo-alpha,epsilon-peptide in interfering with the reverse transcription of eukaryotic mRNA and the noteworthy enzymatic res...
Source: Amino Acids - October 7, 2009 Category: Biochemistry Authors: Roviello GN, Gaetano SD, Capasso D, Cesarani A, Bucci EM, Pedone C Tags: Amino Acids Source Type: journals

Regulation of redox forms of plasma thiols by albumin in multiple sclerosis after fasting and methionine loading test.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study has also demonstrated that albumin-dependent SH/SS exchange reactions are a potent regulation system of thiol redox species in plasma. PMID: 19798466 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - October 1, 2009 Category: Biochemistry Authors: Di Giuseppe D, Ulivelli M, Bartalini S, Battistini S, Cerase A, Passero S, Summa D, Frosali S, Priora R, Margaritis A, Di Simplicio P Tags: Amino Acids Source Type: journals

Changes in plasma amino acid concentrations with increasing age in patients with propionic acidemia.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study gives new insight over long-term changes in plasma amino acid concentrations and may provide options for future therapies (e.g., substitution of anaplerotic substances) in PA patients. PMID: 19795187 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - September 30, 2009 Category: Biochemistry Authors: Scholl-Bürgi S, Sass JO, Heinz-Erian P, Amann E, Haberlandt E, Albrecht U, Ertl C, Sigl SB, Lagler F, Rostasy K, Karall D Tags: Amino Acids Source Type: journals

Plasma levels and urinary excretion of amino acids by subjects with renal calculi.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Plasma levels and urinary amino acid excretions were estimated by high-performance liquid chromatography in 15 control subjects and 36 stone formers (SFs) classified according to the stone type: (1) 22 cases with calcium oxalate stones; (2) four cases with pure uric acid stones; (3) 10 cases with magnesium-ammonium phosphate stones, either pure or mixed with apatite. Some types of stones (namely oxalate and uric acid calculi) are mainly formed as a result of a metabolic deficiency that may affect the amino acid metabolism, and thus may be reflected in the urinary amino acid pattern. Data demonstrated clearly that there...
Source: Amino Acids - September 28, 2009 Category: Biochemistry Authors: Atanassova SS, Panchev P, Ivanova M Tags: Amino Acids Source Type: journals

Synthesis of the siderophore pyoverdine in Pseudomonas aeruginosa involves a periplasmic maturation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Pyoverdines, the main siderophores produced by fluorescent Pseudomonads, comprise a fluorescent dihydroxyquinoline chromophore attached to a strain-specific peptide. These molecules are thought to be synthesized as non-fluorescent precursor peptides that are then modified to give functional pyoverdines. Using the fluorescent properties of PVDI, the pyoverdine produced by Pseudomonas aeruginosa PAO1, we were able to show that PVDI was not present in the cytoplasm of the bacteria, but large amounts of a fluorescent PVDI precursor PVDIp were stored in the periplasm. Like PVDI, PVDIp is able to transport iron into P. aerug...
Source: Amino Acids - September 28, 2009 Category: Biochemistry Authors: Yeterian E, Martin LW, Guillon L, Journet L, Lamont IL, Schalk IJ Tags: Amino Acids Source Type: journals

Medium optimization for production of gamma-aminobutyric acid by Lactobacillus brevis NCL912.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Production of gamma-aminobutyric acid (GABA) was carried out in Erlenmeyer flasks by Lactobacillus brevis NCL912. Traditional methods were first adopted to select the key factors that impact the GABA production to preliminarily determine the suitable concentration ranges of the key factors. It was found that glucose, soya peptone, Tween-80 and MnSO(4).4H(2)O were the key factors affecting GABA production. Then, response surface methodology was applied to analyze the optimum contents of the four key factors in the medium, and the production of GABA was predicted as 349.69 mM under the optimized conditions with this mode...
Source: Amino Acids - September 28, 2009 Category: Biochemistry Authors: Li H, Qiu T, Gao D, Cao Y Tags: Amino Acids Source Type: journals

Effects of zinc ex vivo and intracellular zinc chelator in vivo on taurine uptake in goldfish retina.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study examined the effect of zinc (ZnSO(4)) ex vivo and zinc chelator N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN) in vivo on [(3)H]taurine transport in goldfish retina. The effect of TPEN in vivo on taurine and zinc levels was determined. Isolated cells were incubated in Ringer with zinc (0.1-100 muM). Taurine transport was done with taurine (0.001-1 mM) and 50 nM [(3)H]taurine. Zinc (100 muM) noncompetitively inhibited taurine transport. TPEN was administered intraocularly and retinas extracted 3, 5 and 10 days later. Taurine was determined by HPLC (nmol/mg protein) and zinc by spectrophotometry ICP (...
Source: Amino Acids - September 26, 2009 Category: Biochemistry Authors: Nusetti S, Urbina M, Obregón F, Quintal M, Benzo Z, Lima L Tags: Amino Acids Source Type: journals

In vitro heat shock of human monocytes results in a proportional increase of inducible Hsp70 expression according to the basal content.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, the heat shock response in monocytes is directly proportional to the amount of Hsp70 present in the cells and the stress response may be much higher at different times of the day. PMID: 19779802 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - September 24, 2009 Category: Biochemistry Authors: Vince RV, Oliver K, Midgley AW, McNaughton LR, Madden LA Tags: Amino Acids Source Type: journals

Susceptibility of Pseudomonas aeruginosa to catechol-substituted cephalosporin is unrelated to the pyochelin-Fe transporter FptA.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Previously it has been postulated that the pyochelin-Fe outer membrane transporter, FptA, is involved in the uptake of catechol-substituted cephalosporins in Pseudomonas aeruginosa. Iron uptake and antibacterial activity studies on different mutants showed clearly that FptA is unable to bind and transport these antibiotics. PMID: 19777323 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - September 23, 2009 Category: Biochemistry Authors: Hoegy F, Gwynn MN, Schalk IJ Tags: Amino Acids Source Type: journals

Imaging of human glioma cells by means of a Syndecan-4 directed DOTA-conjugate.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The extracellular glycoprotein Tenascin-C (TN-C) is highly upregulated in gliomas. Therefore, many chemotherapies with radiolabeled antibodies against TN-C have been performed. However, TN-Cs binding partner Syndecan-4 did not play any role as a therapeutic or imaging target in gliomas. We constructed an imaging compound containing the magnetic resonance imaging (MRI) contrast agent gadolinium (Gd)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), the fluorescence dye sulforhodamine and a synthetic Syndecan-4-specific 21 amino acid peptide derived from TN-C. Magnetic resonance relaxometry, confocal laser...
Source: Amino Acids - September 23, 2009 Category: Biochemistry Authors: Sturzu A, Kalbacher H, Echner H, Klose U, Gharabaghi A, Heckl S Tags: Amino Acids Source Type: journals

Urocortin 1 administered into the hypothalamic supraoptic nucleus affects open-field behaviour in rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The presence of both Urocortin 1 (Ucn1) and corticotropin-releasing factor 2 receptors (CRF(2)R) in the hypothalamic supraoptic nucleus (SON) suggests that endogenous Ucn1 released within this brain area acts as a local signal that might be involved in the regulation of not only endocrine but also behavioural stress responses. To test this hypothesis, we monitored the effects induced by the administration of a range of doses of synthetic Ucn1 (0.001-1.0 mug) bilaterally into the SON of rats in the open field test (OFT). Ucn1 administration produced an inverted U-shaped dose-response curve on OFT behaviour, in particula...
Source: Amino Acids - September 21, 2009 Category: Biochemistry Authors: Fatima A, Haroon MF, Wolf G, Engelmann M, Spina MG Tags: Amino Acids Source Type: journals

Adenosine receptor agonists affect taurine release from mouse brain stem slices in ischemia.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The release of the inhibitory amino acid taurine is markedly enhanced under ischemic conditions in both adult and developing brain stem, together with a pronounced increase in the release of the neuromodulator adenosine. We now studied the effects of adenosine receptor agonists and antagonists on [(3)H]taurine release in the brain stem in normoxia and ischemia, using a superfusion system. Under standard conditions, the adenosine A(1) receptor agonist N(6)-cyclohexyladenosine (CHA) potentiated basal taurine release in adult mice, which response was blocked by the antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX). CH...
Source: Amino Acids - September 18, 2009 Category: Biochemistry Authors: Saransaari P, Oja SS Tags: Amino Acids Source Type: journals

Detection of D: -amino acids in purified proteins synthesized in Escherichia coli.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
It has long been believed that amino acids comprising proteins of all living organisms are only of the L: -configuration, except for Gly. However, peptidyl D: -amino acids were observed in hydrolysates of soluble high molecular weight fractions extracted from cells or tissues of various organisms. This strongly suggests that significant amounts of D: -amino acids are naturally present in usual proteins. Thus we analyzed the D: -amino acid contents of His-tag-purified beta-galactosidase and human urocortin, which were synthesized by Escherichia coli grown in controlled synthetic media. After acidic hydrolysis for variou...
Source: Amino Acids - September 18, 2009 Category: Biochemistry Authors: Miyamoto T, Sekine M, Ogawa T, Hidaka M, Homma H, Masaki H Tags: Amino Acids Source Type: journals

Chemiluminescence from thermal oxidation of amino acids and proteins.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Chemiluminescence (CL) with maximum emission in the range 550-650 nm is observed when proteins and certain amino acids are heated in air, and CL intensity is significantly reduced in nitrogen. Of the 20 common amino acids, lysine (Lys) has the highest thermal CL intensity by a factor of ~30 over arginine, threonine and asparagine. This finding differs from previous studies on amino acids and proteins oxidised using free radical initiators or singlet oxygen, where tryptophan was the dominant factor for CL emission. CL from heating solid Lys in air is accompanied by browning and the generation of fluorescent products whi...
Source: Amino Acids - September 17, 2009 Category: Biochemistry Authors: Millington KR, Ishii H, Maurdev G Tags: Amino Acids Source Type: journals

Tryptophan and iodothyronine transport interactions in HepG2 human hepatoma cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study identifies interactions between transport of the aromatic amino acid L: -tryptophan (Trp) and thyroid hormones (TH) in HepG2 human hepatoma cells. The major portion of Trp uptake in HepG2 cells occurs via the NEM-sensitive amino acid transport System L2 (consistent with hepatic LAT3 expression), with a smaller aromatic-AA selective System T (MCT10) component. LAT3 and MCT10 mRNA were both detected in HepG2 cells. Uptake of TH does not involve System L2, but a significant portion of T(3) uptake is mediated by System T, alongside a taurocholate-sensitive organic anion transporter. T(4) uptake into HepG2 cells appe...
Source: Amino Acids - September 14, 2009 Category: Biochemistry Authors: Ritchie JW, Taylor PM Tags: Amino Acids Source Type: journals

Microwave irradiation as a versatile tool for increasing reaction rates and yields in synthesis of optically active polyamides containing flexible L: -leucine amino acid.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this investigation, a series of thermally stable and optically active polyamides (PA)s containing bulky pendant chiral functionality from polymerization of a diacid monomer containing rigid phthalimide and flexible L: -leucine groups, (2S)-5-[4-(4-methyl-2-phthalimidylpentanoylamino)benzoylamino]isophthalic acid with several aromatic and aliphatic diisocyanates such as 4,4'-methylenebis(phenyl isocyanate), toluylene-2,4-diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate under gradual heating method were prepared and compared with microwave-assisted polycondensation method. The polymerization react...
Source: Amino Acids - September 13, 2009 Category: Biochemistry Authors: Mallakpour S, Zadehnazari A Tags: Amino Acids Source Type: journals

Plasma catecholamine and nephrine responses following 7 weeks of sprint cycle training.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The catecholamine metabolites normetanephrine (NMET) and metanephrine (MET) increase in response to acute exercise. However, changes in catecholamine 'nephrines' during sprint training are unclear. Therefore, the aim of this study was to examine the plasma nephrine and catecholamine (noradrenaline, NA; adrenaline, AD) responses to a laboratory-based cycle test before and after a 7-week period of cycle sprint training. Ten healthy men completed a 2-min cycle test at a power output equivalent to 110% of pre-training VO(2)max before and after 7 weeks of laboratory based sprint cycle training, three times per week. Resting...
Source: Amino Acids - September 9, 2009 Category: Biochemistry Authors: Bracken RM, Brooks S Tags: Amino Acids Source Type: journals

Shotgun proteomic analysis of the fat body during metamorphosis of domesticated silkworm (Bombyx mori).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Protein expression profiles in the fat bodies of larval, pupal, and moth stages of silkworm were determined using shotgun proteomics and MS sequencing. We identified 138, 217, and 86 proteins from the larval, pupal and moth stages, respectively, of which 12 were shared by the 3 stages. There were 92, 150, and 45 specific proteins identified in the larval, pupal and moth stages, respectively, of which 17, 68, and 9 had functional annotations. Among the specific proteins identified in moth fat body, sex-specific storage-protein 1 precursor and chorion protein B8 were unique to the moth stage, indicating that the moth sta...
Source: Amino Acids - September 2, 2009 Category: Biochemistry Authors: Yang H, Zhou Z, Zhang H, Chen M, Li J, Ma Y, Zhong B Tags: Amino Acids Source Type: journals

Generation of reactive oxygen species by beta amyloid fibrils and oligomers involves different intra/extracellular pathways.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
PMID: 19728034 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - August 31, 2009 Category: Biochemistry Authors: Cenini G, Cecchi C, Pensalfini A, Bonini SA, Ferrari-Toninelli G, Liguri G, Memo M, Uberti D Tags: Amino Acids Source Type: journals

Oral supplementation with L: -aspartate and L: -glutamate inhibits atherogenesis and fatty liver disease in cholesterol-fed rabbit.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, oral supplementation with L: -aspartate and L: -glutamate inhibits the progression of atherogenesis and the development of fatty liver disease in the animal model of cholesterol-fed rabbit. The beneficial effects of dicarboxylic amino acids reflect the limited elevation of serum gamma-GT activity. PMID: 19701712 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - August 22, 2009 Category: Biochemistry Authors: Yanni AE, Agrogiannis G, Nomikos T, Fragopoulou E, Pantopoulou A, Antonopoulou S, Perrea D Tags: Amino Acids Source Type: journals

Microwave-assisted synthesis and characterization of optically active poly (ester-imide)s incorporating L: -alanine.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Pyromellitic dianhydride (1) was reacted with L-alanine (2) to result [N,N'-(pyromellitoyl)-bis-L: -alanine diacid] (3). This compound (3) was converted to N,N'-(pyromellitoyl)-bis-L: -alanine diacyl chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacyl chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic aromatic diols furnish a series of new PEIs and Co-PEIs in a laboratory microwave oven (Milestone). The resulting polymers and copolymers have inherent viscosities in the range of 0.31-0.53 dl g(-1). These polymers are optically active, thermally s...
Source: Amino Acids - August 22, 2009 Category: Biochemistry Authors: Zahmatkesh S, Hajipour AR Tags: Amino Acids Source Type: journals

Role of the guanidine group in the N-terminal fragment of PTH(1-11).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A series of PTH hybrids containing a diamine [NH(2)(CH(2))( n )NH(2); n = 4, 5, 6] in the C-terminal position was synthesized based on the H-Aib-Val-Aib-Glu-Ile-Gln-Leu-Nle-His-Gln-Har-NH(2) (Har = homoarginine) template. The compounds were pharmacologically characterized at PTH1R receptors for agonist activity. PMID: 19690796 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - August 18, 2009 Category: Biochemistry Authors: Caporale A, Woznica I, Schievano E, Mammi S, Peggion E Tags: Amino Acids Source Type: journals

In vivo biosynthesis of an Ala-scan library based on the cyclic peptide SFTI-1.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study clearly demonstrates the exciting possibility of generating large cyclic peptide libraries in live E. coli cells, and is a critical first step for developing in vivo screening and directed evolution technologies using the cyclic peptide SFTI-1 as a molecular scaffold. PMID: 19685144 [PubMed - as supplied by publisher] (Source: Amino Acids)
Source: Amino Acids - August 13, 2009 Category: Biochemistry Authors: Austin J, Kimura RH, Woo YH, Camarero JA Tags: Amino Acids Source Type: journals

A mouse protein interactome through combined literature mining with multiple sources of interaction evidence.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Protein-protein interactions (PPIs) play crucial roles in a number of biological processes. Recently, protein interaction networks (PINs) for several model organisms and humans have been generated, but few large-scale researches for mice have ever been made neither experimentally nor computationally. In the work, we undertook an effort to map a mouse PIN, in which protein interactions are hidden in enormous amount of biomedical literatures. Following a co-occurrence-based text-mining approach, a probabilistic model-naïve Bayesian was used to filter false-positive interactions by integrating heterogeneous kinds of ...
Source: Amino Acids - August 7, 2009 Category: Biochemistry Authors: Li X, Cai H, Xu J, Ying S, Zhang Y Tags: Amino Acids Source Type: journals

L: -Arginine stimulates proliferation and prevents endotoxin-induced death of intestinal cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study tested the hypothesis that L: -arginine (Arg) may stimulate cell proliferation and prevent lipopolysaccharide (LPS)-induced death of intestinal cells. Intestinal porcine epithelial cells (IPEC-1) were cultured for 4 days in Arg-free Dulbecco's modified Eagle's-F12 Ham medium (DMEM-F12) containing 10, 100 or 350 muM Arg and 0 or 20 ng/ml LPS. Cell numbers, protein concentrations, protein synthesis and degradation, as well as mammalian target of rapamycin (mTOR) and Toll-like receptor 4 (TLR4) signaling pathways were determined. Without LPS, IPEC-1 cells exhibited time- and Arg-dependent growth curves. LPS treatme...
Source: Amino Acids - August 7, 2009 Category: Biochemistry Authors: Tan B, Yin Y, Kong X, Li P, Li X, Gao H, Li X, Huang R, Wu G Tags: Amino Acids Source Type: journals

Toward quantitative characterization of the binding profile between the human amphiphysin-1 SH3 domain and its peptide ligands.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A new structure-based approach was proposed to quantitatively characterize the binding profile of human amphiphysin-1 (hAmph1) SH3 domain-peptide complexes. In this protocol, the protein/peptide atoms were classified into 16 types in terms of their physicochemical meaning and biological function, and then a 16 x 16 atom-pair interaction matrix was constructed to describe 256 atom-pair types between the SH3 domain and the peptide ligand, with atoms from peptide and SH3 domain served as the matrix columns and rows, respectively. Three non-covalent effects dominating SH3 domain-peptide binding as electrostatic, van der Wa...
Source: Amino Acids - August 7, 2009 Category: Biochemistry Authors: He P, Wu W, Wang HD, Yang K, Liao KL, Zhang W Tags: Amino Acids Source Type: journals