Laboratório de Cristalografia de Proteínas, Departamento de Ciências BioMoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
The Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Wales, United Kingdom.
Int J Biol Macromol. 2021 Apr 1;175:406-421. doi: 10.1016/j.ijbiomac.2021.01.180. Epub 2021 Feb 4.
Schistosomiasis is a neglected tropical disease that affects more than 250 million people worldwide. The only drug available for its treatment undergoes first-pass hepatic metabolism and is not capable of preventing reinfection, which makes the search of new therapies urgently needed. Due to the essential role of fumarases in metabolism, these enzymes represent potential targets for developing novel schistosomiasis treatments. Here, we evaluate the expression profiles for class I and class II fumarases from Schistosoma mansoni (SmFH and SmFH, respectively), and report the complete characterization of SmFH. The first SmFH structure in complex with L-malate was determined at 1.85 Å resolution. The significant thermoshift observed for SmFH in the presence of identified ligands makes the differential scanning fluorimetry an adequate technique for ligand screening. A complete kinetic characterization of SmFH was performed, and comparison with the human fumarase (HsFH) revealed differences regarding the turnover number (k). Structural characterization allowed us to identify differences between SmFH and HsFH that could be explored to design new selective inhibitors. This work represents the very first step towards validate the fumarases as drug targets to treat schistosomiasis. Our results provide the structural basis to rational search for selective ligands.
血吸虫病是一种被忽视的热带病，影响着全球超过 2.5 亿人。可用于治疗该病的唯一药物会经历首过肝代谢，并且不能预防再感染，这使得急需寻找新的治疗方法。由于延胡索酸酶在代谢中的重要作用，这些酶代表了开发新型血吸虫病治疗方法的潜在靶点。在这里，我们评估了曼氏血吸虫（SmFH 和 SmFH）的 I 类和 II 类延胡索酸酶的表达谱，并报告了 SmFH 的完整特征。SmFH 与 L-苹果酸的复合物的第一个结构在 1.85Å分辨率下被确定。在存在鉴定出的配体的情况下观察到 SmFH 的显著热移，使得差示扫描荧光法成为筛选配体的合适技术。SmFH 的完整动力学特征被执行，并且与人类延胡索酸酶（HsFH）的比较显示了关于周转率（k）的差异。结构特征允许我们识别 SmFH 和 HsFH 之间的差异，这些差异可以被探索来设计新的选择性抑制剂。这项工作是验证延胡索酸酶作为治疗血吸虫病的药物靶点的第一步。我们的结果为合理寻找选择性配体提供了结构基础。
