来自HeLa S3细胞的一种核DNA内切酶的纯化及性质

Purification and properties of a nuclear DNA endonuclease from HeLa S3 cells.

作者信息

Fischman G J, Lambert M W, Studzinski G P

出版信息

Biochim Biophys Acta. 1979 Apr 12;567(2):464-71. doi: 10.1016/0005-2744(79)90132-3.

Abstract

An endonuclease that can act on calf thymus DNA and circular doublestranded phage PM2 DNA has been isolated from HeLa S3 cell chromatin. Approximately 200-fold purification was achieved by a sequence of subcellular fractionation, differential NaCl solubility and chromatography on CM-Sephadex, DEAE-cellulose and hydroxyapatite, and isoelectric point is pH 5.1 +/- 0.2. Divalent cations are necessary for its activity and the enzyme is heat inactivated at 60 degrees C. The enzyme activity is sensitive to caffeine and sulfhydryl reacting compounds. The molecular weight, determined by gel filtration and SDS gel electrophoresis, is approx. 22 000.

摘要

一种可作用于小牛胸腺DNA和环状双链噬菌体PM2 DNA的核酸内切酶已从HeLa S3细胞染色质中分离出来。通过亚细胞分级分离、不同NaCl溶解度以及在CM-葡聚糖凝胶、二乙氨基乙基纤维素和羟基磷灰石上的层析等一系列操作，实现了约200倍的纯化，其等电点为pH 5.1±0.2。二价阳离子对其活性是必需的，该酶在60℃时热失活。酶活性对咖啡因和巯基反应性化合物敏感。通过凝胶过滤和SDS凝胶电泳测定，其分子量约为22000。