Inhibits the activity of the angiotensin-converting enzyme (ACE) by a preferential interaction with its C-domain. May also potentiate the hypotensive effects of bradykinin. Has much lower activity than BPP-9a. Expressed by the venom gland. This protein seems to be found in newborn B.jararaca venom but not in adult snake venom. BPP-9a. BPP-9a. BPP-9a-F. BPP-9a-F. BPP-12c. The nonapeptide BPP-9a was synthesized under the name SQ-20881. It greatly clarified the importance of ACE in hypertension. However, it's lack of oral activity limits it's therapeutic utility. Bradykinin-potentiating peptide 9a-F is present only in female snakes. Belongs to the bradykinin-potentiating peptide family.