Omega-conotoxins act at presynaptic membranes, they bind and block voltage-gated calcium channels. This toxin blocks N-type calcium channels (Cav2.2/CACNA1B) (PubMed:10938268). Shows a weak voltage-dependent reversibility (PubMed:19892914). It is noteworthy that ancillary subunits beta modulate recovery from this toxin block (PubMed:19892914). Cav2.2/CACNA1B expressed with the ancillary subunit CACNB2a (isoform 2a) shows a low recovery from this toxin block, whereas Cav2.2/CACNA1B expressed with CACNB3 does not exhibit recovery at all (PubMed:19892914). 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). Belongs to the conotoxin O1 superfamily.