Snake venom phospholipase A2 (PLA2) that is the first competitive blocker of nicotinic acetylcholine receptors (nAChRs) (PubMed:21333664). Competes with alpha-bungarotoxin for binding to nAChRs and acetylcholine binding proteins (AChBPs) and blocks acetylcholine-elicited current (PubMed:21333664). PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides (PubMed:21333664). a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 1-acyl-sn-glycero-3-phosphocholine + a fatty acid + H(+) Binds 1 Ca(2+) ion. Monomer. Expressed by the venom gland. Contains 14 disulfide bonds. Accounts for only about 0.5% of dry venom mass. The molecular mass and the number of disulfide bonds are two times greater than that observed for other snake venom PLA2 molecules. This finding suggests that bitanarin may contain 2 repeats of the PLA2 sequence in a single polypeptide chain (PubMed:21333664). Belongs to the phospholipase A2 family. Group II subfamily.