Kinetic Study of the Effect of Histidines 240 and 164 on TEM-149 Enzyme Probed by β-Lactam Inhibitors

Abstract

ABSTRACTIn the present study, we performed a detailed kinetic analysis of the enzymes TEM-149, TEM-149H240, and TEM-149H164-H240versus a large panel of inhibitors/inactivators, including penicillins, penems, carbapenems, monobactams, cephamycin, and carbacephem. These compounds behaved as poor substrates versus TEM-149, TEM-149H240, and TEM-149H164-H240β-lactamases, and theKi(inhibition constant),K(dissociation constant of the Henri-Michaelis complex),k+2andk+3(first-order acylation and deacylation constants, respectively), andk+2/Kvalues were calculated.