On the specificity of human renin. Studies with peptide inhibitors.

The amino acid sequence around the renin substrate site is known to be identical to the N-terminal tetradecapeptide: Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu-Leu-Val-Tyr-Ser. Renin (EC 3.4.99.19) from both primates and non-primates cleaves this peptide at the leucylleucine bond. Several analogs of the octapeptide segment: His-Pro-Phe-His-Leu-Leu-Val-Tyr of this tetradecapeptide act as competitive inhibitors for human renin with inhibition constants down to 1 muM. The same peptides were shown, however, to have no or only slight affinity for non-primate renin. The substrate site has been preserved throughout evolution whereas the enzyme site for human renin is different from that of non-primate renins. The findings suggest that species-specific peptides must be developed for both studies of renin inhibition and for renin purification.