title: γ-Glutamyl Transfer Reactions by Glutaminase from Pseudomonas nitroreducens IFO 12694 and Their Application for the Syntheses of Theanine and γ-Glutamylmethylamide.
abstract: 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.
authors.affiliation: a Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University.
authors.forename: T
authors.initials: T
authors.lastname: Tachiki
authors.affiliation: a Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University.
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.affiliation: a Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University.
authors.forename: K
authors.initials: K
authors.lastname: Mizuno
authors.affiliation: a Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University.
authors.forename: M
authors.initials: M
authors.lastname: Ueda
authors.affiliation: a Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University.
authors.forename: J
authors.initials: J
authors.lastname: Shiode
authors.affiliation: a Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University.
authors.forename: H
authors.initials: H
authors.lastname: Fukami
keywords: Pseudomonas nitroreducens; glutaminase; theanine; γ-glutamyl transfer reaction; γ-glutamylmethylamide