Fairfield F R, Bauer W R, Simpson M V
J Biol Chem. 1979 Oct 10;254(19):9352-4.
A topoisomerase (nicking-closing enzyme) has been isolated from rat liver mitochondria. It has purified by double-stranded DNA-cellulose chromatography approximately 50,000-fold, based on the crude mitochondrial extract. It possesses a minimum specific activity of 1.9 x 10(5) units/mg. The enzyme has been shown to be distinctly mitochondrial, differentiated from the nuclear topoisomerase by its sensitivity to the intercalating drug, ethidium bromide, and to the non-intercalating trypanocidal drug, Berenil.
一种拓扑异构酶（切口封闭酶）已从大鼠肝脏线粒体中分离出来。基于粗制线粒体提取物，通过双链DNA纤维素色谱法将其纯化了约50,000倍。它的最低比活性为1.9×10⁵单位/毫克。已证明该酶明显存在于线粒体中，通过其对嵌入药物溴化乙锭和非嵌入杀锥虫药物贝尼尔的敏感性与核拓扑异构酶区分开来。
