Purification and characterization of three acidic, cytotoxic phospholipases A 2 from Indian cobra ( Naja naja naja) venom

Abstract

Three acidic phospholipases A 2 (NN-I 2c-PLA 2, NN-I 2d-PLA 2 and NN-I 2e-PLA 2) were purified by successive chromatography of Indian cobra ( Naja naja naja) venom on CM–Sephadex C-25, Sephadex G-50 and QAE–Sephadex A-25 columns. They have molecular weights of 13 000–14 500 by sodium dodecyl sulphate–polyacrylamide gel electrophoresis. They showed tryptophan specific fluorescence emission spectra (∼345 nm). All the three phospholipases A 2 were enzymatically highly active with specific activities 9–17 μmol min −1 mg −1. They were non-lethal to mice when injected intraperitoneally in doses up to 10 mg kg −1 body weight. They induced edema in mouse foot pads and were cytotoxic to Ehrlich ascites tumour cells. They did not exhibit direct haemolytic and anticoagulant activities.