Lanuszewska J, Widlak P
Department of Experimental and Clinical Radiobiology, Center of Oncology, Wybrzeze AK 15, 44-100, Gliwice, Poland.
Cancer Lett. 2000 Sep 29;158(1):17-25. doi: 10.1016/s0304-3835(00)00517-6.
High mobility group (HMG) proteins 1 and 2 are abundant non-histone chromosomal proteins that bind preferentially DNA that is bent or underwound. Previous studies have shown that these proteins preferentially bind to DNA damaged by the crosslinking agents cis-diammine-dichloro-platinum(II), chromium(III) and UV-C radiation. Here we have studied the binding of HMG-1/2 proteins to a duplex oligonucleotide damaged by benzo(a)pyrene diol epoxide or N-acetoxy-acetylaminofluorene using an electrophoretic mobility shift assay. Both chemicals induce monoadducts that are known to distort DNA structure. The affinities of HMG-1/2 for DNA damaged by benzo[a]pyrene diol epoxide or N-acetoxy-acetylaminofluorene were similar to that for UV-irradiated DNA, which were an order of magnitude higher than for undamaged DNA. In contrast, DNA modified by dimethyl sulfate was not preferentially recognised by HMG-1/2.
高迁移率族（HMG）蛋白1和2是丰富的非组蛋白染色体蛋白，它们优先结合弯曲或解旋的DNA。先前的研究表明，这些蛋白优先结合由交联剂顺二氨二氯铂（II）、铬（III）和UV-C辐射损伤的DNA。在此，我们使用电泳迁移率变动分析研究了HMG-1/2蛋白与被苯并（a）芘二醇环氧化物或N-乙酰氧基-乙酰氨基芴损伤的双链寡核苷酸的结合。这两种化学物质都会诱导已知会扭曲DNA结构的单加合物。HMG-1/2对被苯并[a]芘二醇环氧化物或N-乙酰氧基-乙酰氨基芴损伤的DNA的亲和力与对紫外线照射的DNA的亲和力相似，比对未损伤DNA的亲和力高一个数量级。相比之下，硫酸二甲酯修饰的DNA不会被HMG-1/2优先识别。
