Open AccessA mutant Bacillus subtilis γ‐glutamyltranspeptidase specialized in hydrolysis activity
Author(s) -
Minami Hiromichi,
Suzuki Hideyuki,
Kumagai Hidehiko
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00456-7
Subject(s) - bacillus subtilis , hydrolysis , glutamine , chemistry , biochemistry , mutant , glutaminase , enzyme , amino acid , biology , bacteria , genetics , gene
γ‐Glutamyltranspeptidase (GGT) catalyzes the hydrolysis of γ‐glutamyl compounds and the transfer of their γ‐glutamyl moieties to amino acids and peptides. The transpeptidation activity of Bacillus subtilis GGT is about 10‐fold higher than its hydrolysis activity. In B. subtilis GGT, substitution of Asp‐445 with Ala abolished its transpeptidation activity. The specific activity for hydrolysis of D445A GGT was 40.2% of that of the wild‐type GGT. The K m value for l ‐glutamine was 15.3 mM. D445A GGT was salt tolerant like the wild‐type GGT. These results indicate that D445A GGT will be highly useful as a ‘glutaminase’ in food industry.