%0 Journal Article %A Blechschmidt, Bernd %A Borneleit, Petra %A Kleber, Hans-Peter %T Purification and characterization of an extracellular β-lactamase produced by Acinetobacter calcoaceticus %D 1992 %J Microbiology, %V 138 %N 6 %P 1197-1202 %@ 1465-2080 %R https://doi.org/10.1099/00221287-138-6-1197 %I Microbiology Society, %X A β-lactamase was purified 430-fold from the culture supernatant of Acinetobacter calcoaceticus by ion exchange chromatography on CM-Sephadex and affinity chromatography on phenylboronic-acid-agarose. The purified enzyme was homogeneous as judged by SDS-PAGE, and was characterized with respect to molecular mass (38 and 41 kDa by gel filtration on Sephadex G-75 and SDS-PAGE, respectively), pH optimum (pH 7·0), temperature optimum (45 °C) and isoelectric point (9·3). The β-lactamase showed mainly cephalosporinase activity. It was inhibited by cloxacillin, carbenicillin, penicillanic acid sulphone (sulbactam) and aztreonam. It was not inhibited by clavulanic acid up to a concentration of 0·25 mM. Neither EDTA nor p-chlormercuribenzoate, up to concentrations of 1 or 100 mM, respectively, affected activity. According to these characteristics, it is a typical CEP-N cephalosporinase. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-138-6-1197