B.t.蛋白的纯化与鉴定

Purification and identification of B.t. protein

通过碱溶、碱解的方法溶解B.t.蛋白,采用60%饱和度的硫酸铵粗提,SephadexG-50层析凝胶分离,加1.5倍的95%乙醇可得晶体沉淀并冻干,所得B.t.蛋白含量为92%,SDS-PAGE电泳图谱显示所纯化的B.t.蛋白分子量为130KD,生物学检测时,幼虫至3铃虫的死亡率均大于90%,生物活性达18000IU/mg,可作抗原用。

B.t. protein was dissolved in alkaline solution, and solid ammonium sulphate was added into the above solution till 60% saturation. The precipitate was separated by Sephadex G-50, washed with 1.5 times of 95% ethanol, and freeze-dried. The content of B.t. toxin was 92%. The SDS-PSGE showed that the molecular of the B.t.protein was 103KD. The death rate of the bollworm with larva to second instar larva was more than 90%, and biological activity was 18 000IU/mg. The B.t. toxin could be uesed as antigen.