Chromogenic Leucyl Substrates for Aminopeptidase and Papain

Abstract

L-leucyl-beta-naphthylamide hydro-chloride and L-leucyl-alpha-naphthylamide hydrochloride were prepared by the mixed anhydride method of peptide synthesis. These chromogenic peptides are hydrolyzed by rat tissue extracts and human serum, urine, and whole saliva as well as by pure papain. The beta-naphthylamide is hydrolyzed more readily by both animal tissue enzymes and by papain. The L-leucyl-beta-naphthylamide is more rapidly hydrolyzed by tissue extracts than previous chromogenic amino peptidase substrates and hence gives promise of useful histochemical application.