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应用柱层析和凝胶过滤的方法，从中华眼镜蛇的粗毒中分离纯化出一个不含磷脂酶Ａ２（ＰＬＡ２）的膜毒素（Ｍｅｍｂｒａｎｅｔｏｘｉｎ，ＭＴ）组分．ＭＴ经电泳鉴定为单一成分．将ｑｄＭＴ与鼠抗人鼻咽癌细胞（ＣＮＥ２）的单克隆抗体（ＢＡＣ５）偶联制备成免疫毒素（ＢＡＣ５－ＭＴ），经间接免疫荧光检测，证实免疫毒素仍保留了很好的生物活性．体外抗癌实验证明，在无Ｃａ２＋培养基中，游离的ＭＴ对ＣＮＥ２和Ｓ１８０细胞均有快速杀伤作用，并且对２种细胞的杀伤作用没有明显的区别，但ＢＡＣ５－ＭＴ同样在无Ｃａ２＋条件下，仅对靶细胞ＣＮＥ２有强烈的杀伤作用（杀伤率达７８．６％），对Ｓ１８０细胞只有很弱的杀伤作用（杀伤率为２１．３％）．结果表明ＢＡＣ５－ＭＴ对ＣＮＥ２细胞有很好的选择性杀伤作用，提示蛇膜毒素在肿瘤的导向治疗中将是一条很有希望的途径．
A non-phospholipase A2 (PLA2) membrane-bound toxin (Membranetoxin, MT) fraction was isolated and purified from the crude venom of C. cobra by column chromatography and gel filtration. MT electrophoresis identified as a single component. The immunotoxin (BAC5-MT) was prepared by coupling qdMT with monoclonal antibody (BAC5) of mouse anti-human nasopharyngeal carcinoma cell (CNE2) .Indirect immunofluorescence assay showed that immunotoxin still retained good biological activity. In vitro anti-cancer experiments showed that in the Ca2 + -free medium, free MT had a rapid killing effect on both CNE2 and S180 cells and no significant difference between the two cell lines, but BAC5-MT was also in the absence of Ca2 + , Killing only target cell CNE2 (killing rate of 78.6%) and weak killing effect (killing rate of 21.3%) on S180 cells. The results show that BAC5-MT has a good selective killing effect on CNE2 cells, suggesting that snake venom toxin in the tumor-oriented treatment will be a promising approach.