title: Affinity of cefmenoxime for beta-lactamases: an analysis.
abstract: The interactions of cefmenoxime with beta-lactamases in comparison with cefotaxime, moxalactam, cefoperazone, and ceftazidime have been determined. On-line computerized microacidimetry allowed determination of the affinity of these compounds with the enzymes, which was characterized by Km values. The beta-lactamases that were used were two cephalosporinases and one penicillinase. Within these data, the cephalosporins could be classified into three groups: (1) those with high affinity for the cephalosporinases and very poor affinity for the penicillinase (cefmenoxime, cefotaxime, and moxalactam); (2) those with moderate affinity for the cephalosporinases and very poor affinity for the penicillinase (ceftazidime); (3) those with poor affinity for all enzymes (cefoperazone). In the case of the penicillinase (TEM-1), only cefoperazone was subject to some hydrolysis.
mesh_terms: D001419:Bacteria / Q000201:enzymology; D015281:Cefmenoxime; D002439:Cefotaxime / Q000031:analogs & derivatives* / Q000378:metabolism; D002510:Cephalosporinase / Q000378:metabolism; D002511:Cephalosporins / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D009070:Moxalactam / Q000378:metabolism; D010405:Penicillinase / Q000378:metabolism; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D002510:Cephalosporinase; D010405:Penicillinase; D001618:beta-Lactamases; D015281:Cefmenoxime; D002439:Cefotaxime; D009070:Moxalactam