title: Beta-lactamases produced by a Pseudomonas aeruginosa strain highly resistant to carbenicillin.
abstract: A Pseudomonas aeruginosa strain isolated at Besançon Hospital, France, proved to be highly resistant to carbenicillin and showed a high hydrolytic activity toward this antibiotic. We clearly demonstrated that two beta-lactamases were synthetized: one of them, constitutive, has its enzymatic activity directed mainly toward penicillins, and carbenicillin appears to be its best substrate (higher V(max)); thus, this beta-lactamase is a "carbenicillinase" that differs from the well-known "TEM-like" enzymes. The isoelectric point of this carbenicillinase is 5.30 +/- 0.03. The other one is an inducible cephalosporinase, very similar to the cephalosporinases usually found in these organisms. Its isoelectric point is 8.66 +/- 0.04. These two enzymes have been separated by affinity chromatography and isoelectric focusing. The kinetic constants were measured by computerized microacidimetry.
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D002228:Carbenicillin / Q000494:pharmacology*; D002510:Cephalosporinase / Q000378:metabolism*; D002846:Chromatography, Affinity; D007525:Isoelectric Focusing; D007700:Kinetics; D010403:Penicillin Resistance; D010405:Penicillinase / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology*
chemical_list: D000581:Amidohydrolases; D002510:Cephalosporinase; D010405:Penicillinase; D002228:Carbenicillin