Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. This toxin inhibits alpha-3-beta-4/CHRNA3-CHRNB4 (IC(50)=3.6-18.38 nM), alpha-6/alpha-3-beta-4 (CHRNA6/CHRNA3-CHRNB2-CHRNB4) (IC(50)=33.9-94.1 nM), and alpha-2-beta-4/CHRNA2-CHRNB4 (IC(50)=4550 nM) nAChRs (PubMed:24200193, PubMed:28603989, PubMed:29925760). The toxin competes with agonists in the orthosteric binding site of alpha-3-beta-4/CHRNA3-CHRNB4 and alpha-6-beta-4/CHRNA6-CHRNB4 (PubMed:30252466). Expressed by the venom duct. The cysteine framework is I (CC-C-C). Alpha4/6 pattern. Unmodified Met-32 is essential for toxin binding to rat alpha-3-beta-4/CHRNA3-CHRNB4 nAChR. An oxidation of this methionine provokes a 13.3-fold decrease in inhibitory potency (IC(50)=245 nM instead of 18 nM). Owing to its potent activity, derivatives of this toxin have a potential in the development of a novel drug. Unfortunately, the oxidation of the methionine is readily to happen during toxin synthesis and oxidation steps as well as under oxidative environment in vivo, which should still be considered to find a solution to this major drawback. This toxin does not show inhibition at neuronal alpha-4-beta-4/CHRNA4-CHRNB4, alpha-4-beta-2/CHRNA4-CHRNB2, alpha-6/alpha-3-beta-2-beta-3 (CHRNA6/CHRNA3-CHRNB2-CHRNB3), alpha-3-beta-2/CHRNA3-CHRNB2, alpha-2-beta-2/CHRNA2-CHRNB2, alpha-9-alpha-10/CHRNA9-CHRNA10, alpha-7/CHRNA7 nAChRs and muscle alpha-1-beta-1-delta-epsilon/CHRNA1-CHRNB1-CHRND-CHRNE nAChR (PubMed:24200193). Belongs to the conotoxin A superfamily.