Omega-conotoxins act at presynaptic membranes, they bind and block voltage-gated calcium channels (Cav). 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). Peptide predicted to begin at Arg-51, but it seems more probable that it begins at Cys-52, since this position corresponds to a dibasic residue cleavage. Belongs to the conotoxin O1 superfamily.