Immunological detection of DNA-protein complexes induced by chromate.
Immunological detection of DNA-protein complexes induced by chromate.
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铬酸盐诱导的 DNA-蛋白质复合物的免疫学检测。
DOI：
10.1093/carcin/10.4.667
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发表时间：
1989
期刊：
影响因子：
4.7
通讯作者：
Costa,M
中科院分区：
文献类型：
--
作者：
Miller3rd,CA;Costa,M
中国仓鼠卵巢(CHO)细胞用铬酸钾处理后，一组精选的非组蛋白与DNA形成络合。最丰富的络合蛋白有一个摩尔。WT为∼45kd，被认为是肌动蛋白。制备了铬酸盐诱导的DNA-蛋白质复合体(DPC)的抗血清，以便于对这些复合体的研究。这种抗血清不是检测早期研究中描述的DPC的主要银染蛋白，而是主要与不银染的酸性95kd蛋白(P95)反应。该抗血清可用于常规检测铬酸盐或其他致癌物产生的P95-DNA复合体的诱生作用。CHO细胞的免疫荧光染色和细胞部分的免疫印迹显示反应性抗原位于细胞核内。抗血清的印迹实验表明，在2-巯基乙醇存在下，铬酸盐诱导的P95-DNA复合体解离，这表明与致癌铂化合物形成的DPC相似。一种还原的铬(可能是Cr3+)可以通过与蛋白质和DNA的氮、氧或硫原子结合而形成DPC。这些结果表明，免疫学检测方法在研究致癌物诱导的特定DNA-蛋白质相互作用方面是有用的。讨论了DPC在致癌过程中的可能相关性。
A select group of non-histone proteins becomes complexed to DNA after Chinese hamster ovary (CHO) cells are treated with potassium chromate. The most abundant complexed protein has a mol. wt of ∼45 kd and is thought to be actin. An antiserum to the chromate-induced DNA-protein complexes (DPCs) was prepared to facilitate the study of these complexes. Rather than detecting the predominant silver-stained proteins of DPCs described in an earlier study, this antiserum reacts primarily with an acidic 95-kd protein (p95) that does not silver stain. The antiserum can be used routinely to assay for the induction of p95-DNA complexes produced by chromate and perhaps by other carcinogens. Iminunofluorescent staining of CHO cells and immunoblotting of cell fractions show the reactive antigens are within the cell nucleus. Blotting experiments with the antiserum indicate the chromate-induced p95-DNA complex dissociates in the presence of 2-mercaptoethanol, suggesting similarity to the DPCs formed by carcinogenic platinum compounds. A reduced species of chromium (probably Cr3+) may form DPCs by binding to the nitrogen, oxygen or sulfur atoms of proteins and DNA. These results illustrate the usefulness of immunological detection methods to study specific DNA-protein interactions induced by carcinogens. The possible relevance of DPCs in the carcinogenic process is discussed.