广西眼镜王蛇毒酸性磷脂酶A_2的分离纯化和性质研究

PURIFICATION AND CHARACTERIZATION OF AN ACIDIC PHOSPHOLIPASE A_2 FROM GUANGXI OPHIOPHAGUS HANNAH(KING COBRA)VENOM

目的 :广西眼镜王蛇毒酸性磷脂酶 A2 的分离纯化和性质研究。方法 :分离纯化采用 Sephadex G- 75 ,CM- Sepharose CL -6 B和 DEAE- Sephadex A- 5 0柱层析法 ;通过电泳 ,磷脂酶 A2 活力测定 ,氨基酸组成测定 ,N端序列分析及药理实验进行性质研究。结果 :从广西眼镜王蛇毒中分离到一种酸性的磷脂酶 A2 (命名为 APL A2 - 1) ,相对分子质量为 146 0 0 u,等电点 5 .4,酶的比活力为 10 8μmol/ m g· min- 1 ,N端序列为 NL IQFGNMIQCTVPGF。它对实验用小白鼠有致死性 (L D5 0 6 .6 m g/ kg) ,具有肌毒性 ,心脏毒性 ,抗血小板聚集活性 ,能诱导水肿形成。结论 :APL A2 - 1生化和药理性质的研究 ,为阐明蛇毒 PL A2结构和功能关系 ,及蛇伤中毒机制 ,打下了良好基础。

Objective:This paper reports the purification and characterization of an acidic phospholipase A 2 from Guangxi Ophiophagus hannah venom Methods:The isolation and purification of phospholipase A 2 was done by successive chromatography on Sephadex G 75,CM Sepharose CL 6B and DEAE Sephadex A 50 column Its characterization researches were done by electrophoresis and phospholipase A 2 activity analysis,amino composition and amino terminal sequences analysis,pharmacology experiments Results:An acidic phospholipase A 2 was isolated from Guangxi Ophiophagus hannah venom(signed as APLA 2 1) Its relative molecular weights were 14 600 u,pI was 5 4,phospholipase A 2 activity was 108 μmol/mg·min 1 ,N terminal sequence was NLIQFGNMIQCTVPGF It may have lethal activity(LD 50 ~6 6 mg/kg) for mouse It could induce edema in mouse foot pads It also exhibits myonecrotic,cardiotoxic and anticoagulant activities Conclusion:The characterization researches of APLA 2 1 will provid a good basis for elucidating the relation of structure and function of PLA 2 from venom,and the mechanism of intoxication after snake bite