Blocks olfactory (CNGA2) and retinal (CNGA1) cyclic nucleotide-gated (CNG) ion channel currents. Does not inhibit retinal (CNGA3) currents. It forms high-affinity contacts with the pore turret region and most likely inhibits CNG channel current by blocking the external entrance to the transmembrane pore. Is really more potent that Pseudecin. Does not affect neither depolarization- nor caffeine-induced contraction arterial smooth muscle. Expressed by the venom gland. Belongs to the CRISP family.