Binds to muscular and neuronal nicotinic acetylcholine receptor (nAChR) and inhibits acetylcholine from binding to the receptor, thereby impairing neuromuscular and neuronal transmission (Ref.2, PubMed:30944155). Reversibly blocks chick and mouse muscle nicotinic acetylcholine receptors (Ref.2, PubMed:30944155). Blocks muscle type nAChR with an IC(50)=30 nM, when heterologously expressed in oocytes (PubMed:30944155). Also binds with high affinity to alpha-7/CHRNA7 nAChRs (PubMed:30944155). In addition, shows a weak inhibition of neuronal alpha-3-beta-2/CHRNA3-CHRNB2 nAChR (IC(50)=2.9 uM) (PubMed:30944155). Selectively binds to alpha-1-delta subunit interface of the mouse muscle nicotinic acetylcholine receptor, with a 10-fold higher affinity for the adult than for the fetal receptors (Ref.2, PubMed:30944155). In vivo, when intraperitoneally injected into mice, causes flaccid paralysis and respiratory distress, followed by death within 2-4 hours (PubMed:30944155). Monomer in solution, homodimer in crystal state. Expressed by the venom gland. LD(50) is 170-280 ug/kg by intraperitoneal injection into mice. Belongs to the snake three-finger toxin family. Long-chain subfamily. Type II alpha-neurotoxin sub-subfamily.