Chikhirzhina G I, Domkina L K, Chigareva N G, Ashmarin I P
Mol Biol (Mosk). 1976 Nov-Dec;10(6):1303-10.
An endogenous Ca2+, Mg2+-dependent factor of enzymic nature (apparently an endonuclease) digests a part of chromatin in the rat liver nuclei producing DNA fragments of an uniform size. After 60 min of incubation at 15 degrees C and pH 7.50 in the presence of 5 mM MgCl2 and 2 mM CaCl2 87-93% of the total chromatin becomes soluble. The insoluble chromatin however contains 70-85% of the in vivo newly synthesized RNA. In regenerating liver the proportion of the insoluble residual chromatin increases while the radioactivity of the newly synthesized DNA in this fraction is highest. Residual chromatin can be solubilized by ultrasonic treatment only. The Ca2+, Mg2+-dependent dissolving factor is not present either in brain or in PMN leucocyte nuclei.
一种内源性的、依赖钙和镁的酶性因子（显然是一种核酸内切酶）可消化大鼠肝细胞核中的部分染色质，产生大小均匀的DNA片段。在5 mM氯化镁和2 mM氯化钙存在的条件下，于15℃和pH 7.50孵育60分钟后，87 - 93%的总染色质可溶解。然而，不溶性染色质含有70 - 85%的体内新合成RNA。在再生肝中，不溶性残留染色质的比例增加，而该部分新合成DNA的放射性最高。残留染色质只能通过超声处理来溶解。钙、镁依赖性溶解因子在脑或多形核白细胞核中均不存在。
