A PLATELET-AGGREGATION INHIBITOR PHOSPHOLIPASE-A(2) FROM RUSSELLS VIPER (VIPERA-RUSSELLI) VENOM - ISOLATION AND CHARACTERIZATION

Yipera russelli venom is reported to contain multiple forms of phospho lipase A(2) (PLA(2)). Three PLA(2)s (VRV-PL-V, VRV-PL-VI and VRV-PL-VI IIa) have been purified and characterized in this laboratory. A PLA(2) (VRV-PL-IIIb) inhibiting platelet aggregation was purified from the s ame venom in two steps involving CM-Sephadex C-25 column chromatograph y followed by gel filtration on Sephadex G-50. VRV-PL-IIIb is a basic (pi 7.3-7.7) isoenzyme, with a mel. wt between 14,000 and 15,000. It i nduced neurotoxic symptoms in experimental mice with an i.p. LD(50) of 5.2 mg/kg body weight. VRV-PL-IIIb inhibits ADP-induced platelet aggr egation in a dose-dependent manner. It induced oedema in the foot pads of mice and is devoid of anticoagulant, myotoxic and direct haemolyti c activities. Antibodies to VRV-PL-IIIb showed a single precipitin lin e against the antigen as well as whole venom. Copyright (C) 1996 Elsev ier Science Ltd