Alpha-conotoxins bind to the nicotinic acetylcholine receptors (nAChR) and inhibit them. This peptide potently blocks muscular nicotinic acetylcholine receptor (CHRNA1-CHRNB1-CHRNG-CHRND), and has no effect on neuronal receptors. It is able to totally displace [125I]-Bgtx from the Torpedo receptor with a complete inhibition in the high micromolar range. It produces a biphasic inhibition curve which fits nicely with a two-site model (Ki of 0.46 and 105 nM). Expressed by the venom duct. The cysteine framework is I (CC-C-C). Alpha4/4 pattern. Has no effect on chimeric alpha-7 (CHRNA7), alpha-3-beta-2 (CHRNA3-CHRNB2) and alpha-4-beta-2 (CHRNA4-CHRNB2). Belongs to the conotoxin A superfamily.