Binds to muscular and neuronal nicotinic acetylcholine receptor (nAChR) and inhibits acetylcholine from binding to the receptor, thereby impairing neuromuscular and neuronal transmission (By similarity). Blocks muscle type nAChR (By similarity). 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.