title: Synthesis of theanine from glutamic acid gamma-methyl ester and ethylamine catalyzed by Escherichia coli having gamma-glutamyltranspeptidase activity.
abstract: Glutamic acid gamma-methyl ester (GAME) was used as substrate for theanine synthesis catalyzed by Escherichia coli cells possessing gamma-glutamyltranspeptidase activity. The yield was about 1.2-fold higher than with glutamine as substrate. The reaction was optimal at pH 10 and 45 degrees C, and the optimal substrate ratio of GAME to ethylamine was 1:10 (mol/mol). With GAME at 100 mmol, 95 mmol theanine was obtained after 8 h.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210093, People's Republic of China. zhangfeiluck@126.com
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.forename: Qing-Zhong
authors.initials: QZ
authors.lastname: Zheng
authors.forename: Qing-Cai
authors.initials: QC
authors.lastname: Jiao
authors.forename: Jun-Zhong
authors.initials: JZ
authors.lastname: Liu
authors.forename: Gen-Hai
authors.initials: GH
authors.lastname: Zhao
mesh_terms: D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005021:Ethylamines / Q000737:chemistry*; D005971:Glutamates / Q000138:chemical synthesis* / Q000737:chemistry; D018698:Glutamic Acid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008738:Methyl Ethers / Q000737:chemistry*; D013379:Substrate Specificity; D013696:Temperature; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
chemical_list: D005021:Ethylamines; D005971:Glutamates; D008738:Methyl Ethers; D018698:Glutamic Acid; C026166:theanine; D005723:gamma-Glutamyltransferase; C041564:ethylamine