Purification and characterization of a neurotoxic phospholipase A2 from Indian cobra (Naja naja naja) venom.

Snake venoms contain multimolecular forms of phospholipase A2 which are diverse with respect to their pharmacological properties. A neurotoxic PLA2 from Naja naja naja venom has been purified in two steps. (1) The whole venom was fractionated on CM-Sephadex C-25 column; 4.6% of the total PLA2 activity recovered was found in the NN-V fraction. (2) The NN-Vb-PLA2 fraction was purified to homogeneity by gel filtration of fraction NN-V on Sephadex G-50. It is a basic protein with a mol. wt between 10,500 and 11,000, and is more toxic than other basic PLA2s purified from Naja naja naja venom. The LD50 of NN-Vb-PLA2 is 0.27 mg/kg body wt. It induced neurotoxic symptoms in experimental mice and is devoid of myotoxic, anticoagulant and edema-inducing activities.