Delta endotoxin of Bacillus thuringiensis subsp. israelensis
Delta endotoxin of Bacillus thuringiensis subsp. israelensis
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苏云金芽孢杆菌亚种 Delta 内毒素。
DOI：
10.1128/jb.161.1.39-46.1985
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发表时间：
1985
影响因子：
3.2
通讯作者：
G. Beaudreau
中科院分区：
文献类型：
--
作者：
J. L. Armstrong;G. Rohrmann;G. Beaudreau
苏云金芽孢杆菌苏云金亚种israelensis，纯化的蛋白酶抗性蛋白，其对蚊子幼虫和培养的蚊子细胞、溶解的红细胞显示出毒性，并且对小鼠是致命的。为了提取蛋白质，将B.苏云金用碱处理Israelensis，中和，并与胰蛋白酶和蛋白酶K孵育。然后通过凝胶过滤和DEAE柱层析纯化。从1g（湿重）培养沉淀中纯化出高达240微克的毒性蛋白。获得了两种密切相关的毒性蛋白：25 a和25 b蛋白。这两种形式在十二烷基硫酸钠-聚丙烯酰胺凝胶中共迁移近25，000道尔顿，血清学相关，并显示出相似的部分蛋白酶消化谱，但可通过DEAE色谱和非变性聚丙烯酰胺凝胶电泳区分。蛋白质测序数据表明25 b蛋白缺少25 a蛋白氨基末端的两个氨基酸。未用蛋白酶处理的碱溶性蛋白质的Western印迹酶联免疫吸附测定表明，毒性25 a和25 b蛋白质是从约28，000道尔顿的较大分子蛋白水解衍生的。碱溶性蛋白质来自B的无晶体菌株。苏云金israelensis和B.苏云金Kurstaki不能与25 A蛋白的抗体发生交叉反应。
From Bacillus thuringiensis subsp. israelensis, a proteinase-resistant protein was purified which exhibited toxicity to larval mosquitoes and cultured mosquito cells, lysed erythrocytes, and was lethal to mice. To extract the protein, a sporulating culture of B. thuringiensis subsp. israelensis was treated with alkali, neutralized, and incubated with trypsin and proteinase K. It was then purified by gel filtration and DEAE column chromatography. Up to 240 micrograms of toxic protein was purified from 1 g (wet weight) of culture pellet. Two closely related forms of toxic protein were obtained: the 25a and 25b proteins. The two forms comigrated near 25,000 daltons in a sodium dodecyl sulfate-polyacrylamide gel, were serologically related, and showed similar partial protease digestion profiles, but were distinguishable by DEAE chromatography and nondenaturing polyacrylamide gel electrophoresis. Protein sequencing data indicated the 25b protein lacked the two amino acids at the amino terminus of the 25a protein. A Western blot enzyme-linked immunosorbent assay of alkali-solubilized proteins that were not treated with proteases suggested the toxic 25a and 25b proteins were proteolytically derived from a larger molecule of about 28,000 daltons. Alkali-solubilized proteins from an acrystalliferous strain of B. thuringiensis subsp. israelensis and from B. thuringiensis subsp. kurstaki failed to cross-react with antibodies to the 25a protein.