A mutant Bacillus subtilis gamma-glutamyltranspeptidase specialized in hydrolysis activity.
gamma-Glutamyltranspeptidase (GGT) catalyzes the hydrolysis of gamma-glutamyl compounds and the transfer of their gamma-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.
Minami
Hiromichi
H
Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.
Suzuki
Hideyuki
H
Kumagai
Hidehiko
H
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli; D005972:Glutaminase / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D012965:Sodium Chloride / Q000494:pharmacology; D005723:gamma-Glutamyltransferase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D012965:Sodium Chloride; D005723:gamma-Glutamyltransferase; D005972:Glutaminase