Haloenol lactones: enzyme-activated irreversible inactivators for serine proteases. Inactivation of alpha-chymotrypsin.

Two haloenol lactones have been shown to inactivate alpha-chymotrypsin by an enzyme-mediated process. According to the postulated mechanism, acylation of the active site serine by the haloenol lactone reveals an alpha-haloketone, which alkylates the enzyme at the active site and renders the enzyme inactive. The inactivation has been shown to require enzymatic activation of the inhibitor to its reactive form to take place within the acyl-enzyme intermediate and to be irreversible.