Inhibition of renin by conformationally restricted analogues of angiotensinogen.

[Cys(5),Cys(10)]Angiotensinogen-(5-14)-peptide analogues and homologues were synthesized, in which a disulphide bond between residues 5 and 10 stabilized a 9-->6 beta-turn proposed for the substrate. These compounds were competitive inhibitors of human and pig renins with K(i) values of the order of 10(-6)-10(-5)m, indicating that the conformation proposed for the substrate is important for the interaction with the enzyme.