Omega-conotoxins act at presynaptic membranes, they bind and block voltage-gated calcium channels (Cav). This toxin blocks N-type calcium channels (Cav2.2/CACNA1B) with high potency. Unexpectedly, it does not show any blocking activity at amphibian neuromuscular junction. In vivo, when intracerebroventricularly injected into mice causes shaking activity, and, at higher doses, causes mild tremors. When injected intramuscularly into fish, it causes paralysis, and, at higher doses, causes death. Expressed by the venom duct. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. The cysteine framework is VI/VII (C-C-CC-C-C). CnVIIH. [Hyp7]-CnVIIA and [Pro7, oxMet12]-CnVIIA. [Pro7]CnVIIA. Found in injectable (milked) (IV) venom. Belongs to the conotoxin O1 superfamily.