PURIFICATION AND CHARACTERIZATION OF PLASMODIUM-BERGHEI DNA TOPOISOMERASE-I AND TOPOISOMERASE-II - DRUG-ACTION, INHIBITION OF DECATENATION AND RELAXATION, AND STIMULATION OF DNA CLEAVAGE
PURIFICATION AND CHARACTERIZATION OF PLASMODIUM-BERGHEI DNA TOPOISOMERASE-I AND TOPOISOMERASE-II - DRUG-ACTION, INHIBITION OF DECATENATION AND RELAXATION, AND STIMULATION OF DNA CLEAVAGE
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DOI：
10.1021/bi00355a001
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发表时间：
1986-04-08
期刊：
影响因子：
2.9
通讯作者：
RIOU, G
中科院分区：
文献类型：
--
作者：
RIOU, JF;GABILLOT, M;RIOU, G
最近有人提出，拓扑异构酶可能是治疗几种疾病的药物的重要靶点。这促使我们提纯和鉴定疟疾病原体疟原虫属原虫红细胞中存在的拓扑异构酶I和II，以便以后在抗疟疾药物分析中使用这些酶系统。伯氏疟原虫是从小鼠红细胞寄生虫中分离纯化的拓扑异构酶。疟原虫拓扑异构酶II由两个亚基组成，分子量约为160K。该酶依赖于ATP和镁离子。松弛、解结、去连接和连接的反应条件与用其他真核细胞中的酶观察到的条件相似。疟原虫拓扑异构酶I是一种单体酶，其Mr为70K-100K。它不依赖于ATP，依赖于K+或Na。镁离子不是松弛所必需的，但会刺激反应。拓扑异构酶II比拓扑异构酶I对药物作用更敏感，最具活性的药物是椭圆碱的衍生物。目前用于人类临床治疗的抗疟疾药物是很差的抑制剂。一些抗肿瘤药物能刺激疟原虫拓扑异构酶II的双链DNA裂解活性，如哺乳动物的拓扑异构酶II。抗疟疾药物没有刺激活性。因此，我们认为疟原虫拓扑异构酶不是抗疟疾药物的良好靶点。
It has recently been suggested that topoisomerases could be important targets for drugs used in several diseases. This prompted us to purify and characterize the topoisomerases I and II present in the erythrocytes of protozoan parasites of the genus Plasmodium, the causative agent of malaria, in order to later use these enzymatic systems in antimalarial drug assays. The topoisomerases were purified from Plasmodium berghei, a parasite of mouse red cells. The Plasmodium topoisomerase II consists of two subunits with a molecular weight of about 160K. The enzyme is ATP- and Mg2+-dependent. The conditions for the reactions of relaxation, unknotting, decatenation, and catenation were found to be similar to those observed with enzymes from other eukaryotic cells. The Plasmodium topoisomerase I is a monomeric enzyme with a Mr of 70K-100K. It is ATP-independent and K+- or Na-dependent. Mg2+ is not required for relaxation but stimulates the reaction. Topoisomerase II was more sensitive to drug action than topoisomerase I. The most active drugs were the ellipticine derivatives. The antimalarial drugs, currently used in human clinical therapy, were poor inhibitors. Some antitumoral drugs stimulated the double-stranded DNA cleavage activity of Plasmodium topoisomerase II, like that of mammalian topoisomerases II. Antimalarial drugs had no stimulating activity. It is therefore suggested that Plasmodium topoisomerases are not good targets for antimalarial drugs.