Topoisomerase I is the predominant nuclear protein from avian erythrocytes that can be covalently linked to DNA.
Topoisomerase I is the predominant nuclear protein from avian erythrocytes that can be covalently linked to DNA.
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拓扑异构酶 I 是禽类红细胞中的主要核蛋白，可与 DNA 共价连接。
DOI：
10.1042/bj2260873
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Muller,MT
中科院分区：
文献类型：
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作者：
Hoepfner,RW;Muller,MT
红细胞核提取液中含有稳定或可能与DNA共价结合的蛋白质。这些蛋白质可以通过一种方法来检测，这种方法最初是为了定量拓扑异构酶与DNA的稳定结合[TraskDiDonato&Muller(1984)EMBO J.3,671-676]。在这份报告中，我们表明，用这种方法在细胞核粗提物中检测到的活性数量主要限于各种形式的拓扑异构酶I。一种形式，50 kDa的蛋白质，与组蛋白H1交配。Western blotting实验表明，染色质中存在50 kDa的拓扑异构酶和105 kDa的拓扑异构酶。此外，在红细胞和胚胎成纤维细胞中，高MR形式和低MR形式之间的比例相对恒定。这些结果表明，多种形式并不是一种组织设置所特有的。
Nuclear extracts of erythrocytes contain proteins which stably or possibly covalently bind to DNA. These proteins can be detected by an assay which was originally developed to quantify stable binding of topoisomerases to DNA [Trask, DiDonato & Muller (1984) EMBO J. 3, 671-676]. In this report, we show that the number of activities detected by this assay in crude extracts of nuclei is limited predominantly to various forms of topoisomerase I. One form, a 50 kDa protein, copurifies with histone H1. Western blotting experiments suggest that the 50 kDa topoisomerase exists in chromatin along with the 105 kDa form. In addition, the ratio between the high and low-Mr forms is relatively constant in erythrocytes and embryonic fibroblasts. These results imply that the multiple forms are not unique to one tissue setting.