大鼠腹水肝癌细胞核中的一种核酸内切脱氧核糖核酸酶活性。

An endodeoxyribonuclease activity in nuclei from rat-ascites hepatoma.

作者信息

Hibino Y, Sugano N

出版信息

Cancer Lett. 1985 Dec;29(3):245-54. doi: 10.1016/0304-3835(85)90134-x.

Abstract

The DNA in nuclei from rat-ascites hepatoma (AH) was rather resistant to endogenous endonucleolytic attack (autodigestion), compared with that in nuclei from normal rat liver (RL). In contrast, by micrococcal nuclease, the DNA in AH nuclei was cleaved in the same manner as in RL nuclei. A 0.6 M NaCl extract was prepared from RL or AH nuclei and subjected to Sephadex G-100 filtration. The resulting-nuclease fraction was separated further into two nuclease fractions, I and II, by CM-Sephadex column chromatography. The activity ratio of II to I was 7.1 for the RL and 2.0 for the AH nuclei. Moreover, the activity of fraction II from the AH nuclei was rather low, compared with that from the RL nuclei. Regenerating-liver nuclei from the normal rat were also assayed in the same way. The results obtained were very similar to those from the AH nuclei. In addition, each of fractions, I and II, cleaved pBR322 DNA of superhelical form; in other words, each had endonucleolytic ability.

摘要

与正常大鼠肝脏（RL）细胞核中的DNA相比，大鼠腹水肝癌（AH）细胞核中的DNA对内源核酸内切酶攻击（自消化）具有较强的抗性。相比之下，用微球菌核酸酶处理时，AH细胞核中的DNA与RL细胞核中的DNA以相同方式被切割。从RL或AH细胞核制备0.6M NaCl提取物，并进行Sephadex G - 100过滤。通过CM - Sephadex柱色谱将所得核酸酶部分进一步分离为两个核酸酶部分，I和II。RL细胞核中II与I的活性比为7.1，AH细胞核中为2.0。此外，与RL细胞核中的部分II活性相比，AH细胞核中的部分II活性相当低。对正常大鼠再生肝细胞核也进行了同样的测定。获得的结果与AH细胞核的结果非常相似。此外，部分I和II中的每一个都能切割超螺旋形式的pBR322 DNA；换句话说，每一个都具有核酸内切酶活性。