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-1/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。
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.
出处
《广西医科大学学报》
CAS
北大核心
2007年第2期189-192,共4页
Journal of Guangxi Medical University
基金
国家自然基金资金资助(No.39970174)
关键词
眼镜王蛇
纯化
性质
碱性蛋白
king cobra venom
purification
characterization
