Affinity Chromatography of Renin Using Inhibitory Renin Substrate Analogs 1

Abstract

Summary

Several short peptide analogs of renin substrate were tested for their ability to inhibit renin in solution and to bind renin in affinity chromatography. The peptides Leu-Leu-Val-Tyr-OCH₃, Leu-Leu-Val-Phe-OCH₃ and Leu-Val-Phe-OCH₃ had in vitro inhibitory activity against both hog and human renin. Kinetic studies of the prototype inhibitor Leu-Leu-Val-Phe-OCH₃ demonstrated classical competitive inhibition, with a K _i of 180 μM. When impure hog renin was eluted from succinylated aminoethyl agarose columns containing co-valently bound Leu-Leu-Val-Phe-OCH₃ or Leu-Val-Phe-OCH₃, the elution of renin activity was delayed in comparison with the elution of inactive contaminating proteins. The binding of human renin to agarose bound inhibitors could also be demonstrated if a longer connecting arm was interposed between the peptide ligand and the supporting polysaccharide.