Properties of three carbenicillin-hydrolysing β-lactamases (CARB) from Pseudomonas aeruginosa: identification of a new enzyme
- 1 January 1981
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Antimicrobial Chemotherapy
- Vol. 7 (1) , 49-56
- https://doi.org/10.1093/jac/7.1.49
Abstract
Three Pseudomonas aeruginosa strains, isolated in Cochin Hospital (Paris), produced constitutive β-lactamases markedly active against carbenicillin (high Vm) which have been designated as carbenicillinases (CARB). These three CARB enzymes have differing isoelectric points: 5·3 (CARB-1; strain Dastier), 5·70 (CARB-2; strain Pousset) and 5·75 (CARB-3; strain Cilote). CARB-1 is very similar to the enzymes biosynthesized by Dalgleish and HL strains, previously described. CARB-2 is similar to these of RPL 11 strain, while CARB-3 appears to be a new 7beta;lactamase. The three CARB enzymes show very similar kinetic constants for a large number of 7β-lactams and for each the high Vm for carbenicillin is always associated with a high Km value (70 to 120 μm), corresponding to a rather low affinity. The molecular weights, determined by gel filtration, are similar for CARB-1 (24,000) and CARB-2 (25,000) but that for CARB-3 is higher (31,000).Keywords
This publication has 1 reference indexed in Scilit:
- Nucleotide sequence of the ampicillin resistance gene of Escherichia coli plasmid pBR322.Proceedings of the National Academy of Sciences, 1978