Thermokinetic evaluation of pyrrolidinedicarboxylic acid inhibiting cefalexin hydrolysis with metallo-β-lactamase L1 from Stenotrophomonas maltophilia

Given the enormous biomedical importance of screening inhibitor of the metallo-β-lactamases (MβLs), we determined the thermokinetic parameters of cefalexin hydrolysis with MβL L1 from Stenotrophomonas maltophilia in the absence and presence of 2,5-pyrrolidinedicarboxylic acid (PDA) as enzyme inhibitor. The presence of PDA caused a value decrease of the rate constant k, and a value increase of the apparent activation energy E (from 33.88 to 35.46 kJ mol−1), activation enthalpy image (from 31.35 to 32.92 kJ mol−1), activation free energy image and activation entropy image (from −201.31 to −196.39 J mol−1 K−1) in comparison with the absence of PDA in the temperature range of 298.15–313.15 K, proposing that the changes of k, E, image and image values can be employed to identify the inhibitors of MβLs.