Kariagina I Iu, Miul'berg A A, Tishchenko L I, Ashmarin I P
Biokhimiia. 1976 Jul;41(6):1136-45.
Digesting of chromosomal DNA of interphase rat liver nuclei by Ca, Mg-dependent endonuclease in situ in the presence of chelating agents results in the appearance of the soluble DNP--up to 30% of the total DNA. In addition, 50% of the chromatin is solubilised after mild ultrasonication. In the absence of the chelating agents the degree of fragmentation is considerably increased. The process is accompanied by a loss of some histone and nonhistone chromosomal proteins; the nonhistone proteins are lost selectively. The preliminary removal of the nuclear membrane and significant part of the proteins by tritone X-100 promotes the chromatin degradation and the appearance of low molecular weight fragments. The DNA-fragments of solubilised chromatin are similar to the DNA-fragments of residual chromatin, but in the presence of the chelating agents the latter does not contain monomeric fragments.
在螯合剂存在的情况下，间期大鼠肝细胞核的染色体DNA在原位被钙、镁依赖性核酸内切酶消化，导致可溶性脱氧核糖核蛋白（DNP）出现——占总DNA的30%。此外，轻度超声处理后，50%的染色质可溶解。在没有螯合剂的情况下，片段化程度显著增加。该过程伴随着一些组蛋白和非组蛋白染色体蛋白的丢失；非组蛋白蛋白被选择性地丢失。用曲通X-100预先去除核膜和大部分蛋白质可促进染色质降解并出现低分子量片段。溶解的染色质的DNA片段与残留染色质的DNA片段相似，但在螯合剂存在的情况下，后者不包含单体片段。
