Affects both voltage-gated (Kv) and calcium-dependent potassium channel activities (KCa), with composite and diversified effects in invertebrate and vertebrate systems (PubMed:12646193). In vivo, intramuscular injection in freshwater fishes (Poecelia pinnata) causes secretion of mucous substances, a reaction already observed in fish with other contryphans (PubMed:12646193). Expressed by the venom duct. The cysteine framework is C-C. Exists in two forms, due to cis-trans isomerization at 3-Cys-Pro-4. The cis isomer is the most abundant and is thus thought to be the functionally relevant conformer. Belongs to the O2 superfamily. Contryphan family.