来自纤细短膜虫的I型拓扑异构酶的纯化及核定位

Purification and nuclear localization of a type I topoisomerase from Crithidia fasciculata.

作者信息

Melendy T, Ray D S

出版信息

Mol Biochem Parasitol. 1987 Jun;24(2):215-25. doi: 10.1016/0166-6851(87)90108-3.

Abstract

A type I topoisomerase has been purified to near homogeneity from the trypanosomatid Crithidia fasciculata. The topoisomerase consists of a single 79 kDa polypeptide. The enzyme does not require divalent cations but is stimulated 10-20 fold by the presence of MgCl2. ATP does not affect enzyme activity, while Berenil, N-ethylmaleimide and ethidium bromide are inhibitory. Immunoblots show that the 79 kDa polypeptide is the most prevalent form of the enzyme in extracts of freshly lysed cells and is immunogenically conserved among a variety of trypanosomes. The topoisomerase was localized to the cell nucleus by double antibody immunofluorescence.

摘要

一种I型拓扑异构酶已从锥虫类生物克氏锥虫中纯化至近乎同质。该拓扑异构酶由一条单一的79 kDa多肽组成。该酶不需要二价阳离子，但MgCl₂的存在可使其活性增强10至20倍。ATP不影响酶活性，而贝尼尔、N - 乙基马来酰亚胺和溴化乙锭具有抑制作用。免疫印迹显示，79 kDa多肽是刚裂解细胞提取物中该酶最普遍的形式，并且在多种锥虫中具有免疫原性保守性。通过双抗体免疫荧光法将该拓扑异构酶定位到细胞核中。