Binds to muscular and neuronal nicotinic acetylcholine receptor (nAChR) and inhibits acetylcholine from binding to the receptor, thereby impairing neuromuscular and neuronal transmission (PubMed:30944155). Blocks muscle type nAChR (PubMed:30944155). Also binds with high affinity to alpha-7/CHRNA7 nAChRs (By similarity). In addition, shows a weak inhibition of neuronal alpha-3-beta-2/CHRNA3-CHRNB2 nAChR (By similarity). 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 (By similarity). In vivo, when intraperitoneally injected into mice, causes flaccid paralysis and respiratory distress, followed by death within 2-4 hours (By similarity). Monomer in solution, homodimer in crystal state. Expressed by the venom gland. Belongs to the snake three-finger toxin family. Long-chain subfamily. Type II alpha-neurotoxin sub-subfamily.