Monomer: shows cytolytic activity. Heterodimer: has no cytolytic activity, but retains most of the alpha-cobratoxin capacity to compete with alpha-bungarotoxin for binding to Torpedo and alpha-7/CHRNA7 nicotinic acetylcholine receptors (nAChRs) as well as to Lymnea stagnalis acetylcholine-binding protein. Monomer, or heterodimer with alpha-cobratoxin (AC P01391); disulfide-linked. Expressed by the venom gland. LD(50) is 1.2 mg/kg by intravenous injection. Is classified as a S-type cytotoxin, since a serine residue stands at position 28 (Ser-29 in standard classification). Belongs to the snake three-finger toxin family. Short-chain subfamily. Type IA cytotoxin sub-subfamily.