Structure and effects of a kinin potentiating fraction F (AppF) isolated from Agkistrodon piscivorus piscivorus venom.

The contractile action of bradykinin on isolated smooth muscles is known to be potentiated by special peptides isolated from snake venoms and other animal sources. A fraction F (AppF) has been derived from Agkistrodon piscivorus piscivorus venom. This fraction does not increase the depressor effect of bradykinin n blood pressure, potentiates the action of bradykinin on isolated guinea-pig ileum and prolongs the duration of relaxation in isolated rat duodenum. This fraction was able to inhibit the conversion of angiotensin I to angiotensin II in vitro. The primary structure of this decapeptide is given.