Role of catalytic function in the antiplatelet activity of phospholipase A2 cobra (Naja naja naja) venom.

Three acidic phospholipases A2 from Indian cobra (Naja naja naja) venom inhibited platelet aggregation in platelet rich plasma induced separately by ADP, collagen and epinephrine with different potencies. The order of inhibition was epinephrine > collagen > ADP. They did not inhibit platelet aggregation induced by arachidonic acid (10 microM).