EFFECT OF NEW PEPTIDE INHIBITORS ON THE RATIO OF ANGIOTENSIN I-CONVERTING AND KININ-DEGRADING ACTIVITIES OF DIPEPTIDYL CARBOXYPEPTIDASE (ANGIOTENSIN-CONVERTING ENZYME)

The effect of N alpha-carboxyalkylated dipeptides on angiotensin-conve rting and kinin-degrading activity of angiotensin-converting enzyme (A CE, dipeptidyl carboxypeptidase) was studied. These inhibitors selecti vely affected ACE-induced hydrolysis of angiotensin I-like and bradyki nin-like (hippuryl-His-Leu and hippuryl-Phe-Arg, respectively) substra tes in microsomal fractions of rat lungs and kidneys and rat blood ser um. The inhibition constants of both types of activity were determined for these enzyme preparations and also for ACE from porcine seminal f luid and highly purified ACE from porcine lung. In all cases high inhi bition selectivity of angiotensin-generating and kininase activities o f ACE was found.