Advances in the Study of Phospholipases A2 from the Venom of Agkistrodon Halys Pallas

Abstract

Three isoenzymes of phospholipases A2 have been isolated from the venom of Agkistrodon halys Pallas, and are named acidic PLA2, neutral PLA2, and basic PLA2, respectively. Research has concentrated on four major areas. 1) Determination of the primary structures of the PLA2s by means of the Edman method and molecular cloning. From these studies many new mutant genes of PLA2 from the venom of Agkistrodon halys Pallas were found. 2) Exploration of the effects of Ca²⁺ on the conformation and function of PLA2s using chemical modification, ultraviolet-difference spectrum and fluorescence spectrum studies. 3) Crystal structure analysis has revealed the three-dimensional structures of PLA2s and provided us with information about structure-function relationships of PLA2s. 4) Further research on the mechanism of PLA2s disclosed that acidic PLA2 affects the function of the cytoskeleton of platelets and the positive charges of basic PLA2 contribute to its hemolytic activity.