Identification and Characterization of Small Molecule Inhibitors of Plasmodium falciparum Dihydroorotate Dehydrogenase
Identification and Characterization of Small Molecule Inhibitors of Plasmodium falciparum Dihydroorotate Dehydrogenase
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DOI：
10.1074/jbc.m804990200
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发表时间：
2008-12-12
影响因子：
4.8
通讯作者：
Clardy, Jon
中科院分区：
文献类型：
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作者：
Patel, Vishal;Booker, Michael;Clardy, Jon
恶性疟原虫是最致命的疟疾形式，每年造成100多万人死亡。疟疾寄生虫无法挽救嘧啶，依靠从头生物合成来生存。二氢乳酸脱氢酶（DHOD）是一种线粒体定位的黄酶，它催化了这一途径的限速步骤，因此是一种有吸引力的抗疟疾化疗靶点。利用基于靶标的高通量筛选，我们已经鉴定出一系列有效的、物种特异性的恶性疟原虫DHOD抑制剂（pfDHOD），这些抑制剂对三种培养的恶性疟原虫菌株（3D7、HB3和Dd2）也有效。通过对转基因疟原虫的二次实验，证实了这些化合物的主要抗疟作用机制是抑制pfDHOD，并通过基于硅结构的对接和位点定向诱变探索了酶抑制的结构基础。化合物介导的细胞毒性未在人真皮成纤维细胞或肾上皮细胞中观察到。这些数据证实了pfDHOD是一种抗疟疾药物靶点，并为开始药物化学工作提供了化学支架。
Plasmodium falciparum causes the most deadly form of malaria and accounts for over one million deaths annually. The malaria parasite is unable to salvage pyrimidines and relies on de novo biosynthesis for survival. Dihydroorotate dehydrogenase (DHOD), a mitochondrially localized flavoenzyme, catalyzes the rate-limiting step of this pathway and is therefore an attractive antimalarial chemotherapeutic target. Using a target-based high throughput screen, we have identified a series of potent, species-specific inhibitors of P. falciparum DHOD (pfDHOD) that are also efficacious against three cultured strains (3D7, HB3, and Dd2) of P. falciparum. The primary antimalarial mechanism of action of these compounds was confirmed to be inhibition of pfDHOD through a secondary assay with transgenic malaria parasites, and the structural basis for enzyme inhibition was explored through in silico structure-based docking and site-directed mutagenesis. Compound-mediated cytotoxicity was not observed with human dermal fibroblasts or renal epithelial cells. These data validate pfDHOD as an antimalarial drug target and provide chemical scaffolds with which to begin medicinal chemistry efforts.