13640-39-6Relevant academic research and scientific papers
γ-Glutamyl Transfer Reactions by Glutaminase from Pseudomonas nitroreducens IFO 12694 and Their Application for the Syntheses of Theanine and γ-Glutamylmethylamide
Tachiki, Takashi,Yamada, Takeshi,Mizuno, Katsushige,Ueda, Masashi,Shiode, Ju-Ichi,Fukami, Hiroshi
, p. 1279 - 1283 (1998)
In a mixture containing γ-glutamyl donor (donor) and γ-glutamyl acceptor (acceptor), the glutaminase of Pseudomonas nitroreducens IFO 12694 simultaneously catalyzed a γ-glutamyl transfer reaction and hydrolysis of the donor. The variation of the activities responding to the concentration of glutathione and glycylglycine indicated that the enzyme might be classified in a group of glutaminases that shows hydrolysis prior to transfer reaction. On the other hand, the results with glutamine and ethylamine or methylamine indicated that the enzyme was active in the transfer reaction with suppressed hydrolysis of glutamine, and suggested the possibility of using the reaction for producing γ-glutamylethylamide (theanine) or γ-glutamylmethylamide (γ-GMA). In fact, in a mixture containing high concentrations of substrates (0.7 M glutamine, 1.5 M ethylamine or methylamine) and 0.5 unit/ml glutaminase (borate buffer pH 11), 270 mM (47 g/L) theanine or 250 mM (38 g/L) γ-GMA was formed in 7 h of incubation at 30°C.
PH-Dependent hydrolase, glutaminase, transpeptidase and autotranspeptidase activities of Bacillus subtilis γ-glutamyltransferase
Morelli, Carlo F.,Calvio, Cinzia,Biagiotti, Marco,Speranza, Giovanna
, p. 232 - 245 (2014/01/23)
γ-Glutamyltransferases (γ-GTs) are heterodimeric enzymes that catalyze the transfer of a γ-glutamyl group from a donor species to an acceptor molecule in a transpeptidation reaction through the formation of an intermediate γ-glutamyl enzyme. In our search for a γ-GT from a generally recognized as safe microorganism suitable for the production of γ-glutamyl derivatives with flavor-enhancing properties intended for human use, we cloned and overexpressed the γ-GT from Bacillus subtilis. In this study, we report the behavior of B. subtilis γ-GT in reactions involving glutamine as the donor compound and various acceptor amino acids. The common thread emerging from our results is a strong dependence of the hydrolase, transpeptidase and autotranspeptidase activities of B. subtilis γ-GT on pH, also in relation to the pKa of the acceptor amino acids. Glutamine, commonly referred to as a poor acceptor molecule, undergoes rapid autotranspeptidation at elevated pH, affording oligomeric species, in which up to four γ-glutamyl moieties are linked to a single glutamine. Moreover, we found that d-glutamine is also recognized both as a donor and as an acceptor substrate. Our results prove that the B. subtilis γ-GT-catalyzed transpeptidation reaction is feasible, and the observed activities of γ-GT from B. subtilis could be interpreted in relation to the known ability of the enzyme to process the polymeric material γ-polyglutamic acid.
Molecular cloning and characterization of γ-Glutamyltranspeptidase from pseudomonas nitroreducens IFO12694
Imaoka, Masashi,Yano, Shigekazu,Okumura, Masashi,Hibi, Takao,Wakayama, Mamoru
experimental part, p. 1936 - 1939 (2011/06/11)
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.
γ-Glutamyl transpeptidase acylation with peptidic substrates: Free energy relationships measured by an HPLC kinetic assay
Morin, Mylene,Rivard, Caroline,Keillor, Jeffrey W.
, p. 3790 - 3801 (2008/09/18)
γ-Glutamyl transpeptidase (GGT, EC 2.3.2.2) is a highly glycosylated heterodimeric enzyme linked to the external cellular membrane that catalyzes the hydrolysis of glutathione as well as the transfer of its γ-glutamyl group to amino acids and dipeptides i
Purification and properties of two isozymes of gamma-glutamyltranspeptidase from Bacillus subtilis TAM-4.
Abe,Ito,Ohmachi,Asada
, p. 1621 - 1625 (2007/10/03)
Two isozymes of gamma-glutamyltranspeptidase, GGT-A and GGT-B, were purified to electrophoretic homogeneity from a culture broth of Bacillus subtilis TAM-4, which produces poly(gamma-glutamic acid) (PGA) de novo. GGT-A was composed of three subunits with molecular weights of 23,000 (I), 39,000 (II), and 40,000 (III). GGT-B was composed of two subunits with molecular weight of 22,000 (I) and 39,000 (II). The N-terminal amino acid sequences of GGT-A subunit I and GGT-B subunit I were very similar. GGT-A subunit II and GGT-B subunit II had an identical N-terminal amino acid sequence. That of GGT-A subunit III showed no similarity to the other subunits. Both GGTs had similar enzymatic properties (optimum pH and temperature: pH 8.8 and 55 degrees C) but showed a significantly different thermal stability at 55 degrees C. Both GGT-A and -B used D-gamma-glutamyl-p-nitroanilide as well as the L-isomer as the gamma-glutamyl donor and used various amino acids and peptides as the acceptor. It was also found that the PGA produced by the strain was hydrolyzed to glutamic acid by its own GGTs.
