Hepatitis C virus, causative agent of chronic viral hepatitis, infects 71 million people worldwide and is divided into seven genotypes and multiple subtypes with sequence identities between 68 to 82%. While older generation direct-acting antivirals had varying effectiveness against different genotypes, the newest NS3/4A protease inhibitors including glecaprevir (GLE) have pan-genotypic activity. The structural basis for pan-genotypic inhibition and effects of polymorphisms on inhibitor potency were not well-known due to lack of crystal structures of GLE-bound NS3/4A or genotypes other than 1. In this study, we determined the crystal structures of NS3/4A from genotypes 1a, 3a, 4a, and 5a in complex with GLE. Comparison with the highly similar grazoprevir indicated the mechanism of GLE's drastic improvement in potency. We found that, while GLE is highly potent against wild-type NS3/4A of all genotypes, specific resistance-associated substitutions (RASs) confer orders of magnitude loss in inhibition. Our crystal structures reveal molecular mechanisms behind pan-genotypic activity of GLE, including potency loss due to RASs at D168. Our structures permit for the first time analysis of changes due to polymorphisms among genotypes, providing insights into design principles that can aid future drug development and potentially can be extended to other proteins.

中文翻译：

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Glecaprevir抑制泛基因型HCV NS3 / 4A蛋白酶的分子和结构机理。

丙型肝炎病毒是慢性病毒性肝炎的病原体，全世界感染7100万人，分为7个基因型和多个亚型，序列同一性在68％至82％之间。尽管老一代的直接作用抗病毒药对不同基因型的疗效各不相同，但最新的NS3 / 4A蛋白酶抑制剂（包括glecaprevir（GLE））具有泛基因型活性。由于缺乏与GLE结合的NS3 / 4A的晶体结构或除1以外的基因型，泛基因型抑制的结构基础和多态性对抑制剂效价的影响尚不清楚。在这项研究中，我们确定了NS3的晶体结构。来自基因型1a，3a，4a和5a的/ 4A与GLE复合。与高度相似的grazoprevir的比较表明，GLE的效力显着提高的机制。我们发现，尽管GLE对所有基因型的野生型NS3 / 4A具有很高的效力，但特定的抗药性相关替代（RAS）却使抑制作用降低了几个数量级。我们的晶体结构揭示了GLE泛基因型活动背后的分子机制，包括由于D168的RAS导致的效能丧失。我们的结构允许首次分析由于基因型之间多态性引起的变化，从而提供对有助于未来药物开发并可能扩展到其他蛋白质的设计原理的深刻见解。