Effect of pH on activities of novel beta-lactamases and beta-lactamase inhibitors against these beta-lactamases.
The effects of acidic conditions on activities of seven beta-lactamases--TEM-1 (class A), KOXY (class A), IMP-1 (class B), AmpC (class C), MOX-1 (class C), OXA-5 (class D), and PSE-2 (class D)--and their inhibitors were measured. The enzymatic activities of KOXY, IMP-1, and MOX-1 at pH 5.8 were slightly lower than those at pH 7.5. However, the activities of PSE-2 and OXA-5 were greatly reduced at pH 5.8. All of the beta-lactamase inhibitors tested had poorer inhibitory activities at pH 5.8 than at pH 7.5 except clavulanic acid for TEM-1.
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D001419:Bacteria / Q000201:enzymology; D019818:Clavulanic Acid; D002969:Clavulanic Acids / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D013407:Sulbactam / Q000494:pharmacology; D000078142:Tazobactam; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D002969:Clavulanic Acids; D004791:Enzyme Inhibitors; D065093:beta-Lactamase Inhibitors; D019818:Clavulanic Acid; D010397:Penicillanic Acid; D001618:beta-Lactamases; D013407:Sulbactam; D000078142:Tazobactam