Edema-producing proteins isolated from Trimeresurus mucrosquamatus snake venom

Seven edema-producing fractions were isolated from Trimeresurus mucrosquamatus snake venom by CM-Sephadex C-50 chromatography and further purified by gel filtration on a Sephadex G-75 column. They were homogeneous as judged by electrophoresis on polyacrylamide gels. The mol. wts were estimated to be 26,900 (Fr. IV-2), 21,500 (Fr. X-2), 23,000 (Fr. XII-2), 21,800 (Fr. XIII-2), 24,600 (Fr. XIV-2), 80,000 (Fr. XVIII-1) and 22,500 (Fr. XXII-2). Fraction IV-2 had weak esterase activity, fractions X-2, XII-2, XIII-2 and XIV-2 possessed proteolytic activity toward casein and fibrinogen, while fractions XVIII-1 and XXII-2 possessed phospholipase A2 activity. Fractions with phospholipase A2 activity had greater edema-producing activity than those with protease and/or esterase activity. It is concluded that the edema caused by T. mucrosquamatus venom may be due to phospholipases A2, proteases and esterases.