5457-95-4Relevant academic research and scientific papers
A novel catalytic ability of γ-glutamylcysteine synthetase of Escherichia coli and its application in theanine production
Miyake, Koichiro,Kakita, Shingo
experimental part, p. 2677 - 2683 (2010/09/11)
γ-Glutamylcysteine synthetase (γGCS, EC 6.3.2.2) catalyzes the formation of γ-glutamylcysteine from L-glutamic acid (Glu) and L-cysteine (Cys) in an ATP-dependent manner. While γGCS can use various amino acids as substrate, little is known about whether it can use non-amino acid compounds in place of Cys. We determined that γGCS from Escherichia coli has the ability to combine Glu and amines to form γ-glutamylamides. The reaction rate depended on the length of the methylene chain of the amines in the following order: n-propylamine > butylamine > ethylamine methylamine. The optimal pH for the reaction was narrower and more alkaline than for the reaction with an amino acid. The newly found catalytic ability of γGCS was used in the production of theanine (γ-glutamylethylamine). The resting cells of E. coli expressing γGCS, in which ATP was regenerated through glycolysis, synthesized 12.1 mm theanine (18 h) from 429 mm ethylamine.
Purification and Characterization of γ-Glutamylmethylamide Synthetase from Methylophaga sp. AA-30
Kimura, Toshio,Sugahara, Isao,Hanai, Katsuyuki,Tonomura, Yuuko
, p. 708 - 711 (2007/10/02)
γ-Glutamylmethylamide synthetase was purified about 70-fold from a cell-free extract of Methylophaga sp.AA-30 by ammonium sulfate fractionation, Octyl-Sepharose column chromatography, and Sephacryl S-300 gel filtration.Only a single protein band was detected after SDS-polyacrylamide gel electrophoresis of the purified preparation; the band was at a position corresponding to a molecular weight of 56,000.The molecular weight of the enzyme was calculated to be 440,000 by Superose 6HR gel filtration, so we suggest that the enzyme is an octomer of identical subunits.The enzyme had maximum activity at pH 7.5 and 40 deg C.It could use ethylamine and propylamine instead of methylamine as the substrate, but it could not use D-glutamate or L-glutamine instead of L-glutamate.
