Inhibition of angiotensin I converting enzyme by venom peptides

The synthetic analogues of three naturally occurring peptides from the venom of Bothrops jararaca have been tested as inhibitors of angiotensin converting enzyme activity in two systems. They have widely differing absolute potencies but the relative potencies are similar in the two systems. The high inhibitory potency of the nonapeptide is compatible with a non-competitive type of inhibition.