DNA-PROTEIN COMPLEXES INDUCED BY CHROMATE AND OTHER CARCINOGENS
DNA-PROTEIN COMPLEXES INDUCED BY CHROMATE AND OTHER CARCINOGENS
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DOI：
10.2307/3431136
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发表时间：
1991-05-01
影响因子：
10.4
通讯作者：
COSTA, M
中科院分区：
文献类型：
--
作者：
COSTA, M
分离、分析了铬酸盐诱导的中国仓鼠卵巢细胞DNA-蛋白质复合体，并与顺铂、紫外线和甲醛诱导的DNA-蛋白质复合体进行了比较。根据肌动蛋白的分子量、等电点、与肌动蛋白多克隆抗体的阳性反应和蛋白分解图谱，肌动蛋白被认为是铬酸盐与DNA络合的主要蛋白质之一。铬酸盐和顺铂都是分子量和等电点相似的复杂蛋白质，这些络合物可以被螯合剂和巯基还原剂破坏，这表明金属本身是参与结合的，而不是具有催化或间接作用(即氧自由基)。相比之下，甲醛将组蛋白与DNA络合，这些络合物不会被螯合剂或还原剂破坏。一种铬酸盐诱导的DNA-蛋白质复合体的抗血清主要与97,000 kDa的蛋白质发生反应，该蛋白质没有银染。缝隙印迹和Western印迹被用于检测p97DNA交联物的形成。所有研究的四种试剂都将这种蛋白质与DNA络合。
DNA-protein complexes induced in intact Chinese hamster ovary cells by chromate have been isolated, analyzed, and compared with those induced by cis-platinum, ultraviolet light, and formaldehyde. Actin has been identified as one of the major proteins complexed to DNA by chromate based upon its molecular weight, isoelectric point, positive reaction with an actin polyclonal antibody, and proteolytic mapping. Chromate and cis-platinum both complex proteins of similar molecular weight and isoelectric points, and these complexes can be disrupted by chelating agents and sulfhydryl reducing agents, suggesting that the metal itself is participating in binding rather than having a catalytic or indirect role (i.e., oxygen radicals). In contrast, formaldehyde complexed histones to the DNA, and these complexes were not disrupted by chelating or reducing agents. An antiserum raised to chromate-induced DNA-protein complexes reacted primarily with 97,000 kDa protein that did not silver stain. Slot blots, as well as Western blots, were used to detect formation of p97 DNA crosslinks. This protein was complexed to the DNA by all four agents studied.