In vitro cytotoxicity of non-Cyt inclusion proteins of a Bacillus thuringiensis isolate against human cells, including cancer cells
In vitro cytotoxicity of non-Cyt inclusion proteins of a Bacillus thuringiensis isolate against human cells, including cancer cells
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DOI：
10.1046/j.1365-2672.2000.01087.x
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发表时间：
2000-07-01
影响因子：
4
通讯作者：
Ohba, M
中科院分区：
文献类型：
--
作者：
Kim, HS;Yamashita, S;Ohba, M
对苏云金芽孢杆菌达科他血清型（H15）的土壤分离物90-F-45-14进行了体外细胞毒性特性的研究，该分离物与伴孢包涵体蛋白有关，对人细胞具有毒性。当被蛋白水解过程激活时，分离物90-F-45-14的包含蛋白对人子宫颈癌细胞（HeLa）表现出中等的细胞毒性，EC 50值为60.8 μ g/ml（-1），同时对人白血病T细胞（MOLT-4）和正常T细胞表现出极高的活性，EC 50值为0.27和0.20 μ g/ml（-1），分别90-F-45-14蛋白的抗白血病细胞活性是B的8 - 9倍。苏云金杆菌以色列血清变种蛋白，含有Cyt 1蛋白，一种广谱溶细胞素。由90-F-45-14蛋白引起的细胞病变的特征在于显著的细胞气球样变，而Israelensis蛋白由于细胞溶解而诱导细胞的早期分解。该分离物的内含物由170、103、73、40和32 kDa的五种主要多肽组成。在170和103 kDa的蛋白质之间的15个N-末端氨基酸的序列中观察到100%的同源性。90-F-45-14蛋白与现有的B的Cry/Cyt蛋白之间没有N端序列同源性。苏云金芽孢杆菌，通过蛋白酶K的蛋白水解加工产生了几种分子量范围为40至28 kDa的蛋白质。
A soil isolate designated 90-F-45-14, belonging to Bacillus thuringiensis serovar dakota (H15), was examined for characterization of in vitro cytotoxicity, associated with parasporal inclusion proteins, against human cells. When activated with proteolytic processing, inclusion proteins of the isolate 90-F-45-14 exhibited a moderate cytotoxicity against the human uterus cervix cancer cells (HeLa) with an EC50 value of 60.8 mu g ml(-1) while showing extremely high activities on the human leukaemic T cells (MOLT-4) and the normal T cells with EC50 values of 0.27 and 0.20 mu g ml(-1), respectively. Anti-leukaemic cell activity of the 90-F-45-14 proteins was eight to nine times greater than that of the B. thuringiensis serovar israelensis proteins containing the Cyt1 protein, a broad-spectrum cytolysin. The cytopathy by the 90-F-45-14 proteins was characterized by marked cell-ballooning, while the israelensis proteins induced early breakdown of the cells due to cytolysis. Inclusions of the isolate consisted of five major polypeptides of 170, 103, 73, 40 and 32 kDa. A 100% homology was observed in the sequence of 15 N-terminal amino acids between the proteins of 170 and 103 kDa. There was no N-terminal sequence homology between 90-F-45-14 proteins and the existing Cry/Cyt proteins of B. thuringiensis, Proteolytic processing by proteinase K yielded several proteins with molecular masses ranging from 40 to 28 kDa.