Assessment Of The Phospholipase A_2 Patterns Of Some Egyptian Snakes Venoms

摘要

Despite of the fact that functionally diverse phospholipase A_2 variants of snake venoms are well characterized at the level of protein and gene sequences; the patterns of individual snake venom PLA_2s are poorly known. We investigated the activity, molecular weights and isoelectric points of the phospholipase A_2s of some medically important snake venoms in Egypt. Portrayal of the phospholipase A_2 activity of the vipers, "Pseudocerastes persicus fieldi, Cerastes cerastes and Echis carinatus" and the elapids "Naja haje, Walterinnesia aegyptia and Naja nigricollis" venoms revealed that: 1- The elapid venoms, with the exception of Naja haje, displayed higher PLA_2 activity than viper venoms; 2- The molecular weights of the phospholipase A_2 variants were close to 14 kDa; 3- The major phospholipase A_2s of Naja nigricollis were basic proteins while those of Walterinnesia aegyptia venom were acidic proteins; 4- The Naja nigricollis and Pseudocerastes persicus fieldi venoms possessed the highest phospholipase A_2 activity while the Walterinnesia aegyptia and Pseudocerastes persicus fieldi had the highest hemolytic activity of the tested elapids and vipers, respectively; 5- The in vitro hemolytic activities of the venoms were inhibited by the heterologous antivenoms, suggesting that the venom hemolytic factor(s) have shared epitopes. The data provided biochemical information of snake venoms phospholipase A_2 which allowed designing procedure for isolation of the phospholipase A_2s to study their pharmacological effects.