Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them (PubMed:10529206). Specifically blocks mammalian nAChR at the alpha-1/delta binding site (PubMed:10529206). Shows very low potency in blocking the alpha-1/gamma binding site (PubMed:10529206). Expressed by the venom duct. The cysteine framework is I (CC-C-C). Alpha3/5 pattern. Amidated; synthetic peptide with a C-terminus free is 6-fold less active than the amidated peptide. Belongs to the conotoxin A superfamily.