一种新的烙铁头蛇毒肌肉毒素

摘要

A novel myotoxin, designated TMPB, was purified from the venom of Trimeresurus mucrosquamatus by Sephadex G-100 superfine gel chromatography and fast protein liquid chromatography (FPLC). The N-terminal sequence of 24 amino acid residues was determined by protein sequencer. The sequence similarities between TMPB and other two phospholipase A2 (PLA2s) previously purified from the same venom were 41.7% and 54.2%, respectively, but TMPB showed no detectable PLA2 hydrolytic activity. Its molecular weight was estimated to be 16 000 by reducing SDS-PAGE and isoelectric point was determined to be 9.2 by isoelectric focusing electrophoresis. TMPB exhibited strong myotoxicity and platelet aggregation inhibiting activity, and the two activities could all be inhibited by heparin.%用分子筛和快速蛋白质液相色谱(FPLC)从烙铁头(Trimeresurus mucrosquamatus)蛇毒中分离了一个新的碱性肌肉毒素, 命名为TMPB.它的分子量为16 000, 等电点为9.2.用蛋白质序列仪测定了其N端24个氨基酸残基, TMPB与其他两个从同种蛇毒中分离到的碱性磷酯酶A2的同源性分别为41.7%和54.2%.TMPB没有明显的磷酯酶A2水解活性, 但它的肌肉毒性和血小板聚集抑制活性却极强, 其肌肉毒性和血小板聚集抑制活性可被肝素所抑制.