The crystal structure of Trypanosoma brucei enolase:: Visualisation of the inhibitory metal binding site III and potential as target for selective, irreversible inhibition
The crystal structure of Trypanosoma brucei enolase:: Visualisation of the inhibitory metal binding site III and potential as target for selective, irreversible inhibition
复制标题
DOI：
10.1016/s0022-2836(03)00752-6
复制
发表时间：
2003-08-15
影响因子：
5.6
通讯作者：
Rigden, DJ
中科院分区：
文献类型：
--
作者：
Giotto, MTD;Hannaert, V;Rigden, DJ
锥虫的糖酵解酶可引起多种医学和农业上的重要疾病，是药物设计的有效靶标。结构数据的可获得性促进了物种特异性抑制剂的设计。仅与寄生虫酶共价结合的不可逆转抑制剂可能会特别有效。在这里，我们测定了布氏锥虫烯醇化酶的晶体结构，结果表明，位于活性中心附近充满水的空腔中的两个半胱氨酸残基被碘乙酰胺修饰，导致催化活性丧失。由于这些残基是锥虫谱系所特有的，这一发现为开发寄生虫特异性的不可逆转结合的烯醇化酶抑制剂开辟了道路。在目前的结构中，催化中心部分被硫酸盐和两个锌离子占据。令人惊讶的是，其中一个锌离子表明存在一个新的二价金属的烯醇酶结合位点。证据表明，这是第一次直接可视化难以捉摸的抑制性金属部位，到目前为止，它的存在只能从动力学数据中推断出来。(C)2003爱思唯尔有限公司。保留所有权利。
The glycolytic enzymes of the trypanosomatids, that cause a variety of medically and agriculturally important diseases, are validated targets for drug design. Design of species-specific inhibitors is facilitated by the availability of structural data. Irreversible inhibitors, that bound covalently to the parasite enzyme alone, would be potentially particularly effective. Here we determine the crystal structure of enolase from Trypanosoma brucei and show that two cysteine residues, located in a water-filled cavity near the active-site, are modified by iodoacetamide leading to loss of catalytic activity. Since these residues are specific to the Trypanosomatidae lineage, this finding opens the way for the development of parasite-specific, irreversibly binding enolase inhibitors. In the present structure, the catalytic site is partially occupied by sulphate and two zinc ions. Surprisingly, one of these zinc ions illustrates the existence of a novel enolase-binding site for divalent metals. Evidence suggests that this is the first direct visualization of the elusive inhibitory metal site, whose existence has hitherto only been inferred from kinetic data. (C) 2003 Elsevier Ltd. All rights reserved.