Binds with high affinity to muscular (alpha-1-beta-1-gamma-delta/CHRNA1-CHRNB1-CHRNG-CHRND) and neuronal (alpha-7/CHRNA7) nicotinic acetylcholine receptor (nAChR) and inhibits acetylcholine from binding to the receptor, thereby impairing neuromuscular and neuronal transmission (PubMed:33672715). Ranges of nAChR inhibition are in nanomolar (competitive binding with alpha-bungarotoxin gives Ki=2.17 nM on muscle nAChR and Ki=26.9 nM on alpha-7) (PubMed:33672715). Also shows low inhibition on GABA(A) receptors (IC(50)~10 uM on all receptors tested: alpha-1-beta-3-gamma-2 (GABRA1-GABRB3-GABRG2), alpha-1-beta-2-gamma-2 (GABRA1-GABRB2-GABRG2), and alpha-3-beta-2-gamma-2 (GABRA3-GABRB2-GABRG2)) (PubMed:33672715). Expressed by the venom gland. Belongs to the snake three-finger toxin family. Long-chain subfamily. Type II alpha-neurotoxin sub-subfamily.