摘要
Screening of the biochemical-pharmacological properties of the crude venom from the snake Lachesis muta indicated the presence of phospholipase A2 (PLA2; 5260 U/mg protein), procoagulant (2630 U/mg protein), platelet aggregating (43 U/mg protein) and caseinolytic activities (6670 U/mg protein). These activities were separated by filtration of the crude venom on Sephacryl S-200. The material containing PLA2 activity was further fractioned by DEAE-cellulose ion exchange chromatography into four active fractions (F-I to F-IV, containing 1.7, 1.2, 0.3, and 0.05 per cent of the crude venom protein, respectively) by stepwise elution with buffers of increasing ionic strength. All fractions presented a molecular weight of approximately 15,000 and isoelectric points in the range pH 4.6-6.0. In addition to their indirect hemolytic activity, the partially purified fractions inhibited platelet aggregation induced either by collagen or thrombin. p-Bromophenacyl bromide-treated fractions lost both phospholipase A2 activity and their inhibitory effect on collagen-induced platelet aggregation
Subject(s)
Animals , Phospholipases A/isolation & purification , Viper Venoms/chemistry , Chromatography, Gel , Chromatography, Ion Exchange , Phospholipases A/pharmacology , Platelet Aggregation , Viper Venoms/enzymology , Viper Venoms/metabolism , Viperidae摘要
Six venoms from snakes of the genus Bothrops were tested for coagulation, platelet aggregation and phospholipase A2 (PLA2) activity. Almost all showed pro-coagulant and PLA2 activities while pro-aggregating properties were found only for some venoms. Bothrops jararaca venom showed different protein peaks associated with these activities. The pro-aggregating activity was inhibited by EDTA, leupeptin and mepacrine while the PLA2 activity was blocked by p-bromophenacyl bromide and 2-mercaptoethanol. Venom screening tests for clotting and platelet aggregation may represent a valuable tool for snake taxonomy and for monitoring the quality of antisera