Binds with high affinity to muscular (IC(50)=114 nM) and neuronal (alpha-7/CHRNA7) (IC(50)=58 nM) nicotinic acetylcholine receptor (nAChR) and inhibits acetylcholine from binding to the receptor, thereby impairing neuromuscular and neuronal transmission. Competitive radioligand binding assays also demonstrate that this toxin competes with epibatidine binding to the Lymnea stagnalis acetylcholine-binding protein (Ls-AChBP) (IC(50)=4.9 nM). Monomer (predominant). Expressed by the venom gland. Amidation does not significantly affect toxin selectivity, since the activity profile and binding data are reminiscent of classical long-chain 3-finger toxins with a free carboxyl termini. Monoisotopic mass. Does not affect alpha-3/beta-2 (CHRNA3/CHRNB2) and alpha-3/beta-4 (CHRNA3/CHRNB4) nAChRs at 1 uM concentrations. Belongs to the snake three-finger toxin family. Long-chain subfamily. Type II alpha-neurotoxin sub-subfamily.