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

 描述（由申请人提供）：丙型肝炎病毒（HCV）是一种病原体，感染全球超过1.5亿人，是慢性肝炎、肝硬化和肝细胞癌的主要原因。HCV是一种遗传多样性病毒，具有6种已知的基因型，其中基因型1和3是最普遍的。这种遗传多样性使得HCV感染难以治疗。在过去的几年中，直接作用的抗病毒药物（DAA）的出现显着改善了治疗选择和治疗结果。然而，尽管有针对多种蛋白质的高效抑制剂，但耐药性是所有药物类别中的主要问题。耐药性是在维持底物加工的同时抑制剂效力的损失。尽管NS 3/4A蛋白酶抑制剂是高度有效的，但它们不是对所有基因型都有效，并且容易受到感染。 耐药性潜在的差异抑制剂效力是耐药性和基因型差异的分子机制。阐明这些是开发蛋白酶抑制剂的关键，避免耐药性，并对所有HCV基因型有效。具体而言，临床开发中的大多数蛋白酶抑制剂含有与蛋白酶的非必需残基接触的P2部分，这在增加效力的同时也增加了它们对赋予耐药性的单位点突变的易感性。我推测，避免与这些残基接触，同时利用与活性位点中未开发区域的接触的蛋白酶抑制剂将导致抑制剂具有增强的效力和更高的耐药性屏障。为了研究这一假设，使用计算技术，我将设计一组具有扩展P4基团的新型蛋白酶抑制剂。然后我将合成并酶法分析这些蛋白酶抑制剂。顶部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抑制剂设计的迭代轮。该项目将提供有关耐药机制的分子见解，以及设计新型蛋白酶抑制剂以有效治疗HCV感染的新策略。

 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.