Binds with high affinity to muscular (tested on Torpedo marmorata, Kd=1.6 nM) and neuronal (chimeric alpha-7/CHRNA7, Kd=3 nM) nicotinic acetylcholine receptor (nAChR) and inhibits acetylcholine from binding to the receptor, thereby impairing neuromuscular and neuronal transmission (PubMed:9305882). Also shows a very weak inhibition on GABA(A) receptors (PubMed:26221036). The toxin (10 uM) inhibits 83% of current in channels composed of alpha-1-beta-3-gamma-2 (GABRA1-GABRB3-GABRG2) subunits, 39% of current in channels composed of alpha-2-beta-2-gamma-2 (GABRA2-GABRB2-GABRG2) subunits, and 33% of current in channels composed of alpha-5-beta-2-gamma-2 (GABRA5-GABRB2-GABRG2) subunits (PubMed:26221036). Expressed by the venom gland. LD(50) is 1.24 mg/kg by intramuscular injection. Belongs to the snake three-finger toxin family. Long-chain subfamily. Type II alpha-neurotoxin sub-subfamily.