Snake venom natriuretic peptide that exhibits hypotensive and vasodepressor activity (By similarity). Recombinant PtNP-a demonstrates a dose-dependent stimulation of cGMP production via the natriuretic peptide receptor-A (NPR1). It also inhibits the angiotensin converting enzyme (ACE). Expressed by the venom gland. Recombinant PtNP-a does not inhibit platelet aggregation. Belongs to the natriuretic peptide family.