title: Cefotetan and beta-lactamases. II. An unusual property: the inactivation of some beta-lactamases by cefotetan.
abstract: Initially, cefotetan interacts with beta-lactamases to form a classical Michaelis complex characterized by a term Ki (the inhibition constant). In a second phase, this complex develops with time to form a new entity devoid of enzymic activity. This new entity may have the structure of an acyl enzyme with variable stability. In the case of TEM-1 and TEM-2 beta-lactamases, the process is progressively and totally reversible. The same phenomena were observed in varying degrees for Pitton's type 2 (PIT-2) penicillinase, OXA-1 and CARB-1. The Klebsiella oxytoca and Proteus vulgaris beta-lactamases are also inactivated by this same process. However, four other cephalosporinases appear to be unaffected by this mechanism.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015313:Cefotetan; D002511:Cephalosporins / Q000494:pharmacology*; D002513:Cephamycins / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D065093:beta-Lactamase Inhibitors
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D002513:Cephamycins; D065093:beta-Lactamase Inhibitors; D015313:Cefotetan