Antagonist of muscle (alpha-1-beta-1-delta-epsilon/CHRNA1-CHRNB1-CHRND-CHRNE) and neuronal (alpha-7/CHRNA7, alpha-3-beta-2/CHRNA3-CHRNB2, alpha-4-beta-2/CHRNA4-CHRNB2) nicotinic acetylcholine receptors (nAChR) (PubMed:20071329). The highest affinity is for human alpha-7/CHRNA7 nAChRs (IC(50)=180 nM), compared to human alpha-1-beta-1-delta-epsilon/CHRNA1-CHRNB1-CHRND-CHRNE nAChR (IC(50)= 550 nM), alpha-3-beta-2/CHRNA3-CHRNB2 nAChR (IC(50)=500 nM), and alpha-4-beta-2/CHRNA4-CHRNB2 nAChR (IC(50)=2.6 uM). Homodimer; non-covalently linked. Expressed by the venom gland. Belongs to the snake three-finger toxin family. Short-chain subfamily. Orphan group VIII (haditoxin) sub-subfamily.