Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. Expressed by the venom duct. The cysteine framework is I (CC-C-C). Alpha4/7 pattern. Exists in 4 forms due to different PTMs (In1907, In1891, In1874, and In1857). Hydroxylation at 'Pro-8' and 'Pro-14' (In1907). Hydroxylation at 'Pro-8' (In1891). Pyrrolidone carboxylic acid at 'Glu-1' and hydroxylation at 'Pro-8' (In1874). Pyrrolidone carboxylic acid at 'Glu-1' (In1857). Belongs to the conotoxin A superfamily.