BIOLOGICAL ACTIVITY OF PEPSTATINS, PEPSTANONE A AND PARTIAL PEPTIDES ON PEPSIN, CATHEPSIN D AND RENIN

Abstract

The inhibition of pepsin, cathepsin D and renin by pepstatins, pepstanone A and their partial peptides is described. A new method using a nonapeptide containing ³H-Val as the substrate was devised for determination of renin activity. The pepstatin partial peptides valyl-valyl-4-amino-3-hydroxy-6-methylheptanoic acid (Val-Val-AHMHA), isovaleryl-valyl-valyl-4-amino-3-hydroxy-6-methylheptanoic acid (IVA-Val-Val-AHMHA) and carbobenzoxyvalyl-valyl-4-amino-3-hydroxy-6-methylheptanoic acid (Z-Val-Val-AHMHA) weakly inhibited proteolysis by pepsin and did not inhibit renin. Pepstatins B, C, E and G were as active as pepstatin A against pepsin and were slightly more active against renin than pepstatin A. Pepstanone A was as active as pepstatin A against pepsin but slightly less active against renin.