Structure-based design of robust cross-genotypic NS3/4A protease inhibitors that avoid resistance

 描述(申请人提供)：丙型肝炎病毒(丙型肝炎病毒)是一种病原体，感染全球超过1.5亿人，是慢性肝炎、肝硬变和肝细胞癌的主要原因。丙型肝炎病毒是一种遗传多样性的病毒，有6种已知的基因类型，其中1和3型是最常见的。这种基因多样性使丙型肝炎病毒感染难以治疗。在过去的几年里，直接作用抗病毒药物(DAA)的出现显著改善了治疗选择和治疗结果。然而，尽管对多种蛋白质有很强的抑制作用，耐药性在所有药物类别中都是一个主要问题。耐药是指在维持底物加工的同时抑制物效力的丧失。尽管NS3/4A蛋白水解酶抑制剂的效力很强，但它们并不是对所有的基因类型都有效，而且对 抗药性。潜在的不同的抑制剂效力是耐药的分子机制和基因差异。阐明这些是开发避免耐药性并对所有丙型肝炎病毒基因有效的蛋白水解酶抑制剂的关键。具体地说，大多数临床开发中的蛋白酶抑制剂含有接触不必要的蛋白酶残基的P2部分，这在增加效力的同时，也增加了它们对导致耐药性的单部位突变的易感性。我假设，避免与这些残基接触，同时利用与活性部位未开发区域的接触的蛋白酶抑制剂将导致具有更强的效力和更高的耐药性障碍的抑制剂。为了研究这一假设，利用计算技术，我将设计一组具有扩展的P4基团的新型蛋白酶抑制剂。然后，我将合成这些蛋白水解酶抑制剂，并对其进行酶学分析。顶部的引线将与蛋白酶共结晶并进行结构分析，以优化计算设计并启动迭代的几轮抑制剂设计。该项目将提供有关耐药机制的分子见解，并为设计有效治疗丙型肝炎病毒感染的新型蛋白酶抑制剂提供新的策略。

 DESCRIPTION (provided by applicant): Hepatitis C virus (HCV), a pathogen that infects over 150 million people worldwide, is the leading cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is a genetically diverse virus with 6 known genotypes with genotypes 1 and 3 being the most prevalent. This genetic diversity makes HCV infection difficult to treat. In the last few years, the advent of direct-acting antivirals (DAAs) has remarkably improved therapeutic options and treatment outcomes. However, despite highly potent inhibitors against multiple proteins, drug resistance is a major problem in all drug classes. Drug resistance is a loss of inhibitor potency while maintaining substrate processing. Though NS3/4A protease inhibitors are highly potent, they are not efficacious against all genotypes and are susceptible to drug resistance. Underlying differential inhibitor potency are the molecular mechanisms of drug resistance and genotypic differences. Elucidating these are key to developing protease inhibitors that avoid drug resistance and are effective against all HCV genotypes. Specifically most protease inhibitors in clinical development contain P2 moieties that contact unessential residues of the protease, which while increasing potency also increases their susceptibility to single site mutations that confer drug resistance. I hypothesize that protease inhibitors that avoid contact with these residues while leveraging contact with unexploited areas in the active site will result in inhibitors with enhanced potency and higher barriers to drug resistance. To investigate this hypothesis, using computational techniques, I will design a panel of novel protease inhibitors with extended P4 groups. I will then synthesize and enzymatically assay these protease inhibitors. Top leads will be co-crystalized with the protease and structurally analyzed to optimize the computational designs and initiate iterative rounds of inhibitor design. This project will provide molecular insights about the mechanisms of drug resistance as well as new strategies for the design of novel protease inhibitors for the effective treatment of HCV infection.