Snake venom neurotoxin that blocks neuromuscular transmission on both avian and mouse nerve-muscle preparations, presenting a postsynaptic action through the nicotinic acetylcholine receptor (nAChR). Reversibly inhibits twitches in mouse phrenic nerve diaphragm and irreversibly in chick biventer cervicis muscle. Has no cytotoxic activity towards C2C12 cells up to 180 ug/ml. Expressed by the venom gland. Contains 4 disulfide bonds. LD(50) is 0.06 mg/kg by intraperitoneal injection into mice. Belongs to the snake three-finger toxin family. Short-chain subfamily.