Prusov A N
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Russia.
Biochemistry (Mosc). 1997 Jun;62(6):667-75.
The effect of UV-irradiation on the chromatin fractionation from DNase I-treated rat liver nuclei by solutions with different concentration of magnesium cations and ionic strengths has been investigated. Comparative analysis of the biochemical parameters of five fractions isolated from irradiated and non-irradiated nuclei has shown marked changes in the amounts of DNA, RNA, and proteins and in the protein composition. UV-Irradiation induces the dose-dependent transition of some chromatin from the S3 and S4 fractions into the insoluble P4 fraction. Chromatin content in fractions soluble in media with high concentrations of magnesium ions (S1 and S2) does not change on irradiation. Decrease in extraction of many proteins after UV-irradiation of both nuclei and preliminary isolated fractions as a consequence of exposure of the nuclei to UV-light may be the result of DNA-protein cross-linkage. A profound effect of UV-irradiation on stabilization of chromatin macrostructure in its condensed regions was observed.
研究了紫外线照射对经脱氧核糖核酸酶I处理的大鼠肝细胞核，在不同浓度镁离子和离子强度溶液中染色质分级分离的影响。对从照射和未照射细胞核中分离出的五个级分的生化参数进行比较分析，结果表明DNA、RNA和蛋白质的含量以及蛋白质组成发生了显著变化。紫外线照射诱导一些染色质从S3和S4级分剂量依赖性地转变为不溶性P4级分。在高浓度镁离子（S1和S2）的培养基中可溶级分中的染色质含量在照射后没有变化。由于细胞核暴露于紫外线下，紫外线照射细胞核和预先分离的级分后许多蛋白质的提取量减少，这可能是DNA-蛋白质交联的结果。观察到紫外线照射对染色质凝聚区域宏观结构的稳定有深远影响。
