- OXYLIPIN-PEPTIDE CONJUGATED MEDIATORS THAT PROMOTE RESOLUTION OF INFECTION, ORGAN PROTECTION AND TISSUE REGENERATION
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A family of bioactive compounds identified in self-resolving inflammatory exudates is disclosed. The compounds give UV chromophores characteristic of a conjugated triene double bond system coupled to an auxochrome allylic to the triene. Further elucidation of the compounds reveals that they have an oxylipin backbone conjugated to a peptide or amino acid moiety via an auxochrome. In some embodiments the auxochrome is sulfur. However, the auxochrome may be NH, CH2 or O. The compounds have potent bioactivity, in vitro, and, in vivo, including promoting resolution of infection, stimulating macrophage phagocytosis of bacteria; protecting tissues from neutrophil mediated damage, promoting tissue repair and regeneration and preventing or limiting second organ reflow/reperfusion damage.
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- Molecular cloning and characterization of γ-Glutamyltranspeptidase from pseudomonas nitroreducens IFO12694
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y-Glutamyltranspeptidase from Pseudomonas nitroreducens IFO12694 (PnGGT) exhibited higher hydro-lytic activity than transfer activity, as compared with other y-glutamyltranspeptidases (GGTs). PnGGT showed little activity towards most of L-amino acids and towards glycyl-glycine, which is often used as a standard y-glutamyl accepter in GGT transfer reactions. The preferred substrates for PnGGT as a y-glutamyl accepter were amines such as methylamine, ethylamine, and isopropylamine.
- Imaoka, Masashi,Yano, Shigekazu,Okumura, Masashi,Hibi, Takao,Wakayama, Mamoru
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experimental part
p. 1936 - 1939
(2011/06/11)
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- Biochemical and structural properties of gamma-glutamyl transpeptidase from Geobacillus thermodenitrificans: An enzyme specialized in hydrolase activity
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Gamma-glutamyltranspeptidases (γ-GTs) catalyze the transfer of the gamma-glutamyl moiety of glutathione and related gamma-glutamyl amides to water (hydrolysis) or to amino acids and peptides (transpeptidation) and play a key role in glutathione metabolism. Recently, γ-GTs have been considered attractive pharmaceutical targets for cancer and useful tools to produce γ-glutamyl compounds. To find out γ-GTs with special properties we have chosen microorganisms belonging to Geobacillus species which are source of several thermostable enzymes of potential interest for biotechnology. γ-GT from Geobacillus thermodenitrificans (GthGT) was cloned, expressed in Escherichia coli, purified to homogeneity and characterized. The enzyme, synthesized as a precursor homotetrameric protein of 61-kDa per subunit, undergoes an internal post-translational cleavage of the 61 kDa monomer into 40- and 21-kDa shorter subunits, which are then assembled into an active heterotetramer composed of two 40- and two 21-kDa subunits. The kinetic characterization of the hydrolysis reaction using l-glutamic acid γ-(4-nitroanilide) as the substrate reveals that the active enzyme has Km 7.6 μM and Vmax 0.36 μmol min/mg. The optimum pH and temperature for the hydrolysis activity are 7.8 and 52 °C, respectively. GthGT hydrolyses the physiological antioxidant glutathione, suggesting an involvement of the enzyme in the cellular defense mechanism against oxidative stress. Unlike other γ-GTs, the mutation of the highly conserved catalytic nucleophile, Thr353, abolishes the post-translational cleavage of the pro-enzyme, but does not completely block the hydrolytic action. Furthermore, GthGT does not show any transpeptidase activity, suggesting that the enzyme is a specialized γ-glutamyl hydrolase. The GthGT homology-model structure reveals peculiar structural features, which should be responsible for the different functional properties of the enzyme and suggests the structural bases of protein thermostability.
- Castellano,Merlino, Antonello,Rossi, Mosè,La Cara, Francesco
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experimental part
p. 464 - 474
(2011/11/30)
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- Purification and properties of soluble and bound γ- glutamyltransferases from radish cotyledon
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Soluble and cell wall bound γ-glutamyltransferases (GGTs) were purified from radish (Raphanus sativus L.) cotyledons. Soluble GGTs (GGT I and II) had the same Mr of 63,000, and were composed of a heavy subunit (Mr, 42,000) and a light one (Mr, 21,000). The properties of GGT I and II were similar. Bound GGTs (GGT A and B) were purified to homogeneity from the pellet after the extraction of soluble GGTs. GGT A and B were monomeric proteins with an Mr of 61,000. The properties of GGT A and B were similar. Thus, bound GGTs were distinguished from soluble GGTs. The optimal pHs of soluble and bound GGTs were about 7.5. Both soluble and bound GGTs utilized glutathione, γ-L-glutamyl-p-nitroanilide, oxidized glutathione and the conjugate of glutathione with monobromobimane as substrates, and were inhibited by acivicin, but soluble GGTs were also distinguished from bound GGTs with regard to these properties.
- Nakano, Yoshihiro,Okawa, Satoshi,Yamauchi, Takayoshi,Koizumi, Yukio,Sekiya, Jiro
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p. 369 - 376
(2008/02/10)
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- Protease inhibitory polypeptides derived from urinary trypsin inhibitor and compositions thereof
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This invention provides a novel polypeptide which comprises an amino acid sequence that constitutes a portion of urinary trypsin inhibitor (UTI) and which has no antigenicity against human and high activity to inhibit various proteases, as well as other novel polypeptides having excellent activities to inhibit various proteases obtained by mutation of the former novel polypeptide. This invention also provides novel enzyme inhibition processes, drug compositions and treating methods making use of the novel polypeptide, DNA fragments containing nucleotide sequences which encode the novel polypeptides, vectors containing the DNA fragments and transformants transformed with the DNA fragments or the vectors, as well as processes for the production of the novel polypeptides.
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- Characterization of novel isocyanate-derived metabolites of the formamide N-formylamphetamine with the combined use of electrospray mass spectrometry and stable isotope methodology
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Bioactivation of the formamide N-formylamphetamine (NFA) to 1-methyl-2- phenylethyl isocyanate (MPIC) was investigated in rats by screening bile and urine for conjugates subsequent to the phase I event. NFA was administered to rats as a mixture of protio- and pentadeuteriophenyl analogues to gain insight into the carbamoylating activity of MPIC when traced by electrospray liquid chromatography/mass spectrometry (LC/MS). An LC/MS contour generated by recording the summed mass spectrum as a function of chromatographic retention time allowed four biliary metabolites to be identified from four sets of doublets, with the peak of each doublet offset by 5 amu and ca. 0.07 min. Tandem mass spectrometry experiments allowed these metabolites to be attributed structurally to the glutathione, cysteinylglycine, cysteine, and N-acetylcysteine conjugates of the isocyanate MPIC. These assignments were subsequently validated by comparison of the LC/MS properties of the metabolites to synthetic reference compounds. Only the carbamoylated N- acetylcysteine conjugate was detected in urine. The observed excretion in bile of all metabolites of the mercapturate pathway is novel for formamide metabolism. NFA can thus be added to the short list of compounds that are eliminated in this fashion. Factors envisioned as contributory to this metabolic profile in bile include hepatorenal, enterohepatic, and biliary- hepatic cycling, in addition to possible equilibrium exchange of the isocyanate from thiocarbamate conjugates to endogenous free thiols during the course of biliary transit.
- Borel,Abbott
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p. 891 - 899
(2007/10/03)
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- Improved efficiency and selectivity in peptide synthesis: Use of triethylsilane as a carbocation scavenger in deprotection of t-butyl esters and t-butoxycarbonyl-protected sites
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The use of triethylsilane as a carbocation scavenger in the presence of trifluoroacetic acid in dichloromethane leads to increased yields, decreased reaction times, simple work-up and improved selectivity for the deprotection of t-butyl ester and t-butoxycarbonyl sites in protected amino-acids and peptides in the presence of other acid-sensitive protecting groups such as the benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, O- and S-benzyl and t-butylthio groups.
- Mehta, Anita,Jaouhari, Rabih,Benson, Timothy J.,Douglas, Kenneth T.
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p. 5441 - 5444
(2007/10/02)
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