Structural elucidation of the specificity of the antibacterial agent triclosan for malarial enoyl acyl carrier protein reductase
Structural elucidation of the specificity of the antibacterial agent triclosan for malarial enoyl acyl carrier protein reductase
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DOI：
10.1074/jbc.m112000200
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发表时间：
2002-04-12
影响因子：
4.8
通讯作者：
Sacchettini, JC
中科院分区：
文献类型：
--
作者：
Perozzo, R;Kuo, M;Sacchettini, JC
人类疟疾寄生虫恶性疟原虫利用一种在人类中不存在的II型途径合成脂肪酸。脂肪酸延伸的最后一步是由烯酰酰基载体蛋白还原酶催化的，这是一种有效的抗菌药物靶标。在这里，我们报道了恶性疟原虫烯酰酰基载体蛋白还原酶基因的克隆和表达，该基因编码一个50 kda的蛋白（PfENR），预测针对独特的寄生虫顶质体。纯化后的PfENR结晶，其结构分解为与NADH的二元配合物，与三氯生和NAD（+）的三元配合物，以及与NADH结合的三氯生类似物1和2的三元配合物。在ppfr结合环区发现了与细菌同源物最相似的新结构特征；其他地方的蛋白质与甘蓝型油菜（Brassica napus）的ENR相似（Calphas的均方根为0.30埃）。三氯生及其类似物1和2在体外以亚至低微摩尔浓度杀灭红细胞内恶性疟原虫多药耐药菌株。这些数据明确了三氯生与PfENR结合的结构基础，将有助于PfENR抑制剂的结构优化。
The human malaria parasite Plasmodium falciparum synthesizes fatty acids using a type II pathway that is absent in humans. The final step in fatty acid elongation is catalyzed by enoyl acyl carrier protein reductase, a validated antimicrobial drug target. Here, we report the cloning and expression of the P. falciparum enoyl acyl carrier protein reductase gene, which encodes a 50-kDa protein (PfENR) predicted to target to the unique parasite apicoplast. Purified PfENR was crystallized, and its structure resolved as a binary complex with NADH, a ternary complex with triclosan and NAD(+), and as ternary complexes bound to the triclosan analogs 1 and 2 with NADH. Novel structural features were identified in the PfENR binding loop region that most closely resembled bacterial homologs; elsewhere the protein was similar to ENR from the plant Brassica napus (root mean square for Calphas, 0.30 Angstrom). Triclosan and its analogs 1 and 2 killed multidrug-resistant strains of intra-erythrocytic P. falciparum parasites at sub to low micromolar concentrations in vitro. These data define the structural basis of triclosan binding to PfENR and will facilitate structure-based optimization of PfENR inhibitors.