Open AccessBiochemical characterization of the carbapenem‐hydrolyzing β‐lactamase AsbM1 from Aeromonas sobria AER 14M: a member of a novel subgroup of metallo‐β‐lactamases
Author(s) -
Yang Youjun,
Bush Karen
Publication year - 1996
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 - 10.1111/j.1574-6968.1996.tb08105.x
Subject(s) - chemistry , isoelectric point , aeromonas , carbapenem , hydrolysis , cephalosporin , biochemistry , enzyme , microbiology and biotechnology , bacteria , biology , antibiotics , genetics
AsbM1, a carbapenem‐hydrolyzing β‐lactamase produced by Aeromonas sobria AER 14M, was purified chromatographically, with anion exchange chromatography performed in the absence of Zn 2+ . The molecular mass of AsbM1 was approximately 34000; the isoelectric point was 9.1. AsbM1 had high hydrolytic specificity for carbapenems but low hydrolysis rates for penicillins and cephalosporins. AsbM1 was resistant to the commercially available β‐lactamase inhibitors but was inhibited by pCMB and the chelators EDTA and o ‐phenanthroline. Zinc, an activator for many metallo‐β‐lactamases, inhibited AsbM1 with an IC 50 of 8 μM. Analysis of the N‐terminal sequence (27 amino acids) showed 26% similarity to the CphA metallo‐β‐lactamase. Because of the high specificity for carbapenems and the sensitivity to inhibition by Zn 2+ , AsbM1 should be included in a new subgroup of metallo‐β‐lactamases.