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Imipenem is a widely used carbapenem antibiotic clinically. In an effort to probe the antibiotic resistance in bacteria, we first report in this paper the thermokinetic parameters of the imipenem hydrolysis with B1 subclass metallo-β-lactamase CcrA from Bacteroides fragilis. The values of activation free energy are 87.540 ± 0.027, 88.781 ± 0.031, 89.901 ± 0.036, and 91.057 ± 0.021 kJomol-1 at 293.15, 298.15, 303.15, and 308.15 K, respectively, the activation enthalpy is 19.099 ± 0.005 kJomol-1, the activation entropy is -233.57 ± 0.09 Jomol-1oK-1 and the apparent activation energy E is 21.598 kJomol-1. The results indicated that the imipenem hydrolysis by CcrA was an exothermic and spontaneous reaction with order of 1.4 and had higher activation enthalpy and lower activation entropy than the cefazolin hydrolysis. |
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Keywords:Microcalorimetry;Metallo-β-lactamase CcrA;Antibiotic hydrolysis;Imipenem;Thermokinetic parameters |
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