Glutamine

Luận văn này nghiên cứu tổng hợp được phức chất của các nguyên tố đất hiếm (La, Nd, Sm, Gd) với Lglutamin. Bằng các phương pháp phân tích nguyên tố; phân tích nhiệt; phổ hấp thụ hồng ngoại; đo độ dẫn điện. Khảo sát ảnh hưởng của phức chất H3[La(Gln)3(NO3)3].5H2O đến sự phát triển mầm hạt đỗ tương. Mời các bạn cùng tham khảo!

60p thehungergames 16-08-2021 20 3   Download

Certain amino acids, like glutamine and leucine, induce an anabolic response in liver. They activate p70 ribosomal protein S6 kinase (p70S6K) and acetyl-CoA carboxylase (ACC) involved in protein and fatty acids synthesis, respectively. In contrast, the AMP-activated protein kinase (AMPK), which senses the energy state of the cell and becomes activated under metabolic stress, inactivates by phosphorylation key enzymes in biosynthetic pathways thereby conserving ATP.

9p system191 01-06-2013 50 5   Download

Liver metabolism is influenced by hormones and nutrients. Amino acids such as glutamine or leucine induce an anabolic response, which resembles that of insulin in muscle and adipose tissue. In this work, the signalling pathways and the effects of insulin were compared to those of glutamine and leucine in isolated hepatocytes from normal and streptozotocin-diabetic rats.

9p system191 01-06-2013 47 5   Download

Frog p26olf is a novel S100-like Ca21-binding protein found in olfactory cilia. It consists of two S100-like domains aligned sequentially, and has a total of four Ca21-binding sites (known as EF-hands). In this study, to elucidate the mechanism of Ca21-binding to each EF-hand (named EF-A, -B, -C and -D from the N-terminus of p26olf), we examined Ca21-binding in wild-type p26olf and also in its mutants in which a glutamate at the –z coordinate position within each Ca21-binding loop was substituted for a glutamine.

8p system191 01-06-2013 29 4   Download

Transglutaminase (TGase) catalyses the post-translational modification of proteins by transamidation of available glutamine residues. While several TGase genes of fish and arthropods have been cloned and appear to have similar structures to those of mammals, no homologous gene has been found in lower eukaryotes. We have cloned the acellular slime mold Physarum polycephalum TGase cDNA using RT-PCR with degenerated primers, based on the partial amino acid sequence of the purified enzyme. The cDNA contained a 2565-bp ORF encoding a 855-residue polypeptide.

10p research12 01-06-2013 48 4   Download

CTP synthase catalyzes the reaction glutamine + UTP +ATPfiglutamate + CTP + ADP + Pi.The rate of the reaction is greatly enhanced by the allosteric activator GTP.We have studied the glutaminase half-reactionofCTP synthase from Lactococcus lactisand its response to the allosteric activator GTP and nucleotides that bind to the active site. In contrast to what has been found for the Escherichia colienzyme, GTP activation of the L. lactis enzyme did not result in similarkcat values for the glutami-nase activity and glutamine hydrolysis coupled to CTP synthesis. ...

8p research12 29-04-2013 44 2   Download

The structurally homologous mononuclear iron and man-ganese superoxide dismutases (FeSOD and MnSOD, respectively) containa highly conservedglutamine residue in the active site which projects toward the active-site metal centre and participates in an extensive hydrogen bonding network. The position of this residue is different for each SOD isoenzyme (Q69 in FeSOD and Q146 in MnSOD of Escherichia coli).

12p tumor12 22-04-2013 47 3   Download

An activity that inhibited both glutamine synthetase (GS) and nitrate reductase (NR) was highly purified from cauli-flower (Brassica oleraceavar.botrytis) extracts.The final preparationcontainedanacyl-CoAoxidase andasecond proteinof theplant nucleotidepyrophosphatase family.This preparationhydrolysedNADH, ATPandFAD togenerate AMP andwas inhibited by fluoride, Cu 2+ ,Zn 2+ andNi 2+ .

7p tumor12 20-04-2013 32 1   Download

Glutamine synthetase (GS) is expressed at high levels in subsets of cells in some tissues and at low levels in all cells of other tissues, suggesting that the GS gene is surrounded by multiple regulatory elements.We searched for such elements in the 2.5-kbupstreamregionand in the 2.6-kbfirst intronof theGSgene, usingFTO-2Bhepatoma andC2/7muscle cells as representatives of both cell types and transient transfec-tion assays as our tools.

7p tumor12 20-04-2013 43 3   Download

Cytidine 5¢-triphosphate synthase catalyses the ATP-dependent formation of CTP from UTP using either ammonia orL-glutamine as the source of nitrogen. When glutamine is the substrate, GTP is required as an allosteric effector to promote catalysis. Limited trypsin-catalysed proteolysis, Edman degradation, and site-directed muta-genesis were used to identify peptide bonds C-terminal to three basic residues (Lys187, Arg429, and Lys432) of Escherichia coliCTP synthase thatwere highly susceptible to proteolysis. ...

12p fptmusic 16-04-2013 39 4   Download

Glutamine is an essential amino acid for enterocytes, especially in states of critical illness and injury. In several studies it has been speculated that the beneficial effects of glutamine are dependent on the route of supply (lumi-nal or systemic). The aim of this study was to investigate the relevance of both routes of glutamine delivery toin vitro intestinal cells and to explore the molecular basis for proposed beneficial glutamine effects: (a) by deter-mining the relative uptake of radiolabelled glutamine in Caco-2 cells;...

15p fptmusic 11-04-2013 47 2   Download

Ammonium assimilation inEscherichia coliis regulated through multiple mechanisms (metabolic, signal transduction leading to covalent modification, transcription, and translation), which (in-)directly affect the activities of its two ammonium-assimilating enzymes, i.e. glutamine synthetase (GS) and glutamate dehydrogenase (GDH).

21p awards 06-04-2013 29 4   Download

GTP is an allosteric activator of CTP synthase and acts to increase thekcat for the glutamine-dependent CTP synthesis reaction. GTP is suggested, in part, to optimally orient the oxy-anion hole for hydrolysis of glutamine that takes place in the glutamine amidotransferase class I (GATase) domain of CTP synthase.

9p awards 05-04-2013 42 3   Download

Human kynurenine aminotransferase I/glutamine trans-aminase K (hKAT-I) is an important multifunctional enzyme. This study systematically studies the substrates of hKAT-I and reassesses the effects of pH, Tris, amino acids anda-keto acids on the activity of the enzyme. The experi-ments were comprised of functional expression of the hKAT-I in an insect cell/baculovirus expression system, purification of its recombinant protein, and functional characterization of the purified enzyme.

11p awards 05-04-2013 41 4   Download

Glutamine is an essential amino acid in cancer cells and is required for the growth of many other cell types. Glutami-nase activity is positively correlated with malignancy in tumours andwith growth rate in normal cells. In the present work, Ehrlich ascites tumour cells, and their derivative, 0.28AS-2 cells, expressing antisense glutaminase mRNA, were assayed for apoptosis induced by methotrexate and hydrogen peroxide. It is shown that Ehrlich ascites tumour cells, expressing antisense mRNA for glutaminase, contain lower levels of glutathione than normal ascites cells. In addition, 0.

9p awards 05-04-2013 47 4   Download

Cytidine 5¢-triphosphate (CTP) synthase catalyses the ATP-dependent formation of CTP from uridine 5¢-triphosphate using either NH3orL-glutamine as the nitrogen source. The hydrolysis of glutamine is catalysed in the C-terminal glu-tamine amide transfer domain and the nascent NH3that is generated is transferred via an NH3 tunnel [Endrizzi, J.A., Kim, H., Anderson, P.M. & Baldwin, E.P. (2004) Biochemistry43, 6447–6463] to the active site of the N-ter-minal synthasedomainwhere theaminationreactionoccurs....

9p awards 05-04-2013 32 3   Download

The specificity of the Spodoptera frugiperda digestive b-glycosidase (Sfbgly50) for fucosides, glucosides and galactosides is determined by noncovalent interactions of glycone6-OHandglycone 4-OHwith the active-site residues Q39andE451.Site-directedmutagenesisandenzymesteady-state kinetics were described, showing that replacement of E451 with glutamine increased the preference of Sfbgly50 for glucosides in comparison to galactosides, whereas replacing E451 with serine had the opposite effect.

9p awards 05-04-2013 46 3   Download

We investigated structural and functional aspects of the first mutation in TNNC1, coding for the calcium-binding subunit (cTnC) of cardiac tropo-nin, which was detected in a patient with hypertrophic cardiomyopathy [Hoffmann B, Schmidt-Traub H, Perrot A, Osterziel KJ & Gessner R (2001) Hum Mut17, 524]. This mutation leads to a leucine–glutamine exchange at position 29 in the nonfunctional calcium-binding site of cTnC.

11p dell39 27-03-2013 50 5   Download

Wheat endoxylanase inhibitor TAXI-I inhibits microbial glycoside hydro-lase family 11 endoxylanases. Crystallographic data of an Aspergillus niger endoxylanase-TAXI-I complex showed His374 of TAXI-I to be a key resi-due in endoxylanase inhibition [Sansen S, De Ranter CJ, Gebruers K, Brijs K, Courtin CM, Delcour JA & Rabijns A (2004)J Biol Chem279, 36022– 36028]. Its role in enzyme–inhibitor interaction was further investigated by site-directed mutagenesis of His374 into alanine, glutamine or lysine....

11p dell39 27-03-2013 32 5   Download

The protein ataxin-3 is responsible for spinocerebellar ataxia type 3, a neu-rodegenerative disease triggered when the length of a stretch of consecutive glutamines exceeds a critical threshold. Different physiologic roles have been suggested for this protein. More specifically, recent papers have shown that the highly conserved N-terminal Josephin domain of ataxin-3 binds ubiquitin and has ubiquitin hydrolase activity, thanks to a catalytic device specific to cysteine proteases.

10p inspiron33 25-03-2013 35 5   Download