中文摘要：

目的：广西眼镜王蛇毒一种碱性蛋白的分离纯化和性质研究。方法：分离纯化采用DEAE-Sepharose CL-6B离子交换柱层析，Sephadex G-75凝胶过滤和CM-Sepharose CL-6B离子交换柱层析；通过电泳，磷脂酶A2（PLA2）酶活力测定，氨基酸组成分析，N端序列测定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电泳纯的碱性蛋白（命名为CM-IV），相对分子质量约为14000，等电点约为8．65；PLA2的比活力为23μmol·mg^-／min。氨基酸组成分析表明，其分子中Cys的含量占6．85％；利用蛋白质直接测序N端序列为TKCYVTPDVK。药理实验表明它对实验用小白鼠有致死性（LD50约为0．2mg／kg），并具有心脏毒性，但无血小板抑制活性。根据Genebank Blast分析软件，它的N端序列与神经毒素具有高度的同源性。结论：这种碱性蛋白可能为神经毒素，但却拥有PLA2的活力。

英文摘要：

Objective： To purify and characterize a basic protein from Guangxi King cobra（Ophiophagus hannah） venom. Methods. Isolation and purification of a basic protein was done by successive chromatography on DEAE-Sepharose CL-6B, Sephadex G-75 and CM-Sepharose CL-6B column. The characterizations of this protein were studied by electrophoresis, phospholipase A2 activity analysis, amino acid analysis, N-terminal sequence analysis and pharmacology experiments. Result： A basic protein named CM-IV was isolated from Guangxi king cobra venom. Its relative molecular weight was 14 000, pI was 8.65, phospholipase A2 activity was 23μmol·mg^-1/min. Analysis of the amino acid showed that the percentage of Cys was 6.85%. N-terminal sequence was TKCYVTPDVK. This basic pr.otein has lethal activity（LD50≈0.2 mg/kg） for mouse. It exhibits cardiotoxic activities, but not anticoagulant activities. According Genebank Blast, we found that N-terminal sequence of this basic protein shares high amino acid homology with long neurotoxin. Conclusion： These results indicate that this protein maybe neurotoxin, but has weak phospholipase A2 activity.