Mugumbate Grace, Mendes Vitor, Blaszczyk Michal, Sabbah Mohamad, Papadatos George, Lelievre Joel, Ballell Lluis, Barros David, Abell Chris, Blundell Tom L, Overington John P
European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, United Kingdom.
Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
Front Pharmacol. 2017 Sep 26;8:681. doi: 10.3389/fphar.2017.00681. eCollection 2017.
Mycobacterium phenotypic hits are a good reservoir for new chemotypes for the treatment of tuberculosis. However, the absence of defined molecular targets and modes of action could lead to failure in drug development. Therefore, a combination of ligand-based and structure-based chemogenomic approaches followed by biophysical and biochemical validation have been used to identify targets for phenotypic hits. Our approach identified EthR and InhA as targets for several hits, with some showing dual activity against these proteins. From the 35 predicted EthR inhibitors, eight exhibited an IC below 50 μM against EthR and three were confirmed to be also simultaneously active against InhA. Further hit validation was performed using X-ray crystallography yielding eight new crystal structures of EthR inhibitors. Although the EthR inhibitors attain their activity against by hitting yet undefined targets, these results provide new lead compounds that could be further developed to be used to potentiate the effect of EthA activated pro-drugs, such as ethionamide, thus enhancing their bactericidal effect.
结核分枝杆菌的表型活性物质是治疗结核病新化学类型的良好来源。然而，缺乏明确的分子靶点和作用模式可能导致药物开发失败。因此，基于配体和基于结构的化学基因组学方法相结合，随后进行生物物理和生化验证，已被用于确定表型活性物质的靶点。我们的方法确定EthR和InhA为几种活性物质的靶点，有些对这些蛋白质表现出双重活性。在35种预测的EthR抑制剂中，8种对EthR的IC低于50μM，3种被证实对InhA也同时具有活性。使用X射线晶体学进行了进一步的活性物质验证，得到了8种EthR抑制剂的新晶体结构。尽管EthR抑制剂通过作用于尚未明确的靶点来实现其活性，但这些结果提供了新的先导化合物，可进一步开发用于增强EthA激活的前药（如乙硫异烟胺）的效果，从而增强其杀菌作用。
