罗尔斯通氏菌菌株H16新杀虫蛋白的纯化及活性测定

Purification and Activity Identification of a Novel Insecticidal Protein from Ralstonia eutropha H16

利用(NH4)2SO4盐析、超滤、Sephacryl-400HR凝胶过滤层析及DEAE-Sephadex A-50阴离子交换层析等方法,从罗尔斯通氏菌菌株H16(Ralstonia eutropha H16)中分离纯化出一种新的杀虫毒素蛋白。生物活性测定结果表明,此杀虫毒素蛋白存在于胞内和胞外上清液中,电泳结果显示胞内和分泌到胞外的杀虫毒素可能是同一种物质。此毒素对菜青虫初孵幼虫有较强的口服毒性,LD50为2.7mg/头。SDS-PAGE图谱显示此杀虫毒素是由两个亚基组成的复合蛋白。

A novel insecticidal protein was separated and purified by （NH4）2SO4 salting-out extraction, ultrafiltration, Sephacryl-400HR gel filtration and DEAE-Sephadex A-50 anion-exchange chromatography from Ralstonia eutropha H16. The bioassay results showed that this insecticidal protein both existed in intracellular and extracellular supernatant. The electrophoresis results revealed that intracellular and extracellular insecticidal protein might be same protein. This protein had strong oral toxicity to pieris and LD50 was 2.7 mg. The result of SDS-PAGE indicated that this insecticidal protein contained two subunits.