A new inhibitor design strategy for carboxypeptidase A as exemplified by N-(2-chloroethyl)-N-methylphenylalanine.
N-(2-Chloroethyl)-N-methylphenylalanine was designed and synthesized in an optically active form as a novel class of mechanism-based inactivator for carboxypeptidase A (CPA). It was anticipated that the chloroethylamino moiety of the CPA bound inhibitor undergoes an intramolecular SN2 reaction to generate a chemically reactive species (an aziridinium ion) which is expectedly subjected to a nucleophilic attack by the carboxylate of Glu-270, leading to covalent modification of the carboxylate. The irreversible nature of the inhibition of CPA by the inhibitor was supported by the kinetic data: the enzyme lost its enzymic activity in a time-dependent manner in the presence of the inhibitor and the inactivated CPA failed to regain the activity upon dialysis. Interestingly, the (R)-isomer that belongs to the D-series was more potent than its enantiomer.
Park
J D
JD
Center for Biofunctional Molecules and Department of Chemistry, Pohang University of Science and Technology, South Korea.
Lee
K J
KJ
Kim
D H
DH
D000818:Animals; D002268:Carboxypeptidases / Q000037:antagonists & inhibitors*; D043422:Carboxypeptidases A; D020134:Catalytic Domain; D002417:Cattle; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D007700:Kinetics; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000494:pharmacology*; D013379:Substrate Specificity
D004791:Enzyme Inhibitors; C431768:N-(2-chloroethyl)-N-methylphenylalanine; D010649:Phenylalanine; D002268:Carboxypeptidases; D043422:Carboxypeptidases A