title: Change in substrate preference of Streptomyces aminopeptidase through modification of the environment around the substrate binding site.
abstract: We attempted to alter the substrate preference of aminopeptidase from Streptomyces septatus TH-2 (SSAP). Because Asp198 and Phe221 of SSAP are located in the substrate binding site, we screened 2,000 mutant enzymes with D198X/F221X mutations. By carrying out this examination, we obtained two enzymes; one specifically hydrolyzed an arginyl derivative, and the other specifically hydrolyzed a cystinyl derivative (65- and 12.5-fold higher k(cat) values for hydrolysis of p-nitroanilide derivatives than those of the wild type, respectively).
authors.affiliation: Research Institute for Biological Sciences (RIBS), Okayama, 7549-1 Kibichuo-cho, Kaga-gun, Okayama 716-1241, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Arima
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Uesugi
authors.forename: Masaki
authors.initials: M
authors.lastname: Iwabuchi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hatanaka
mesh_terms: D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001665:Binding Sites; D001709:Biotechnology / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D000626:Aminopeptidases