Active-site labelling of kallikreins by chloromethylketone derivatives

Ala-Phe-Lys-CH2-Cl is a chloromethylketone derivative which is able to promote the inhibition of several proteolytic enzymes. In this paper the inhibition of horse urinary and plasmatic kallikreins is described and this inhibition is compared to that produced in human plasma kallikrein. This compound was designed based upon the structure of bradykinin. This enzyme substrate system can provide a model for the study of the interactions between bradykinin and its receptor. The inhibition of the enzymes was achieved both for its esterase and kinin-releasing activities.