Biochemical properties of a penicillin beta-lactamase mediated by R factor from Bordetella bronchiseptica.

The beta-lactamase specified by an R(te16) plasmid in Bordetella bronchiseptica was purified 200-fold by carboxymethyl-Sephadex column chromatography and electrofocusing. The enzyme has a molecular weight of 46,000 +/- 3,000 and an isoelectric point of 8.3 and was highly active against phenethicillin, oxacillin, and propicillin. The enzyme activity was inhibited by sodium chloride but not by ferrous ion. The maximal enzyme activity to benzylpenicillin was observed at pH 7.0 to 7.5 and at 40 C. It is concluded that this enzyme is different from the R-mediated beta-lactamases, i.e., the type I and type II beta-lactamases which have been classified in previous papers.