title: Novel metallo beta-lactamase mediated by a Shigella flexneri plasmid.
abstract: Novel carbapenem-hydrolyzing beta-lactamase (newly named MET-1) encoded on a transferable plasmid pMS390 from Shigella flexneri JS19622 was purified. The molecular weight was 28,000 by SDS-PAGE and the isoelectric point was higher than 9.3. This beta-lactamase favorably hydrolyzed classical cephalosporins and oxyimino-cephalosporins rather than penicillins and carbapenems, but did not hydrolyze monobactams. The enzymatic activity was inhibited by EDTA, and the enzyme was found to contain two moles of zinc per mole of enzyme protein by means of atomic absorption spectrophotometry. These results indicated that the enzyme is a zinc beta-lactamase which differs from known metallo beta-lactamases, especially in its cephalosporinase-type substrate profile.
authors.affiliation: Division of Microbial Chemistry, Faculty of Pharmaceutical Sciences, Chiba University, Japan. oharak@p.chiba-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: O'Hara
authors.forename: S
authors.initials: S
authors.lastname: Haruta
authors.forename: T
authors.initials: T
authors.lastname: Sawai
authors.forename: M
authors.initials: M
authors.lastname: Tsunoda
authors.forename: S
authors.initials: S
authors.lastname: Iyobe
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000378:metabolism; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000096:biosynthesis; D012763:Shigella flexneri / Q000187:drug effects / Q000201:enzymology*; D014169:Transformation, Bacterial; D001618:beta-Lactamases / Q000302:isolation & purification* / Q000378:metabolism; D047090:beta-Lactams / Q000378:metabolism / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D047090:beta-Lactams; D001618:beta-Lactamases