Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan.
Department of Biochemical Science and Technology, National Chiayi University, Chiayi, Taiwan.
Biochem Biophys Res Commun. 2022 Feb 5;591:130-136. doi: 10.1016/j.bbrc.2020.12.106. Epub 2021 Jan 6.
The coronavirus disease (COVID-19) pandemic, resulting from human-to-human transmission of a novel severe acute respiratory syndrome coronavirus (SARS-CoV-2), has led to a global health crisis. Given that the 3 chymotrypsin-like protease (3CLpro) of SARS-CoV-2 plays an indispensable role in viral polyprotein processing, its successful inhibition halts viral replication and thus constrains virus spread. Therefore, developing an effective SARS-CoV-2 3CLpro inhibitor to treat COVID-19 is imperative. A fluorescence resonance energy transfer (FRET)-based method was used to assess the proteolytic activity of SARS-CoV-2 3CLpro using intramolecularly quenched fluorogenic peptide substrates corresponding to the cleavage sequence of SARS-CoV-2 3CLpro. Molecular modeling with GEMDOCK was used to simulate the molecular interactions between drugs and the binding pocket of SARS-CoV-2 3CLpro. This study revealed that the V of SARS-CoV-2 3CLpro was about 2-fold higher than that of SARS-CoV 3CLpro. Interestingly, the proteolytic activity of SARS-CoV-2 3CLpro is slightly more efficient than that of SARS-CoV 3CLpro. Meanwhile, natural compounds PGG and EGCG showed remarkable inhibitory activity against SARS-CoV-2 3CLpro than against SARS-CoV 3CLpro. In molecular docking, PGG and EGCG strongly interacted with the substrate binding pocket of SARS-CoV-2 3CLpro, forming hydrogen bonds with multiple residues, including the catalytic residues C145 and H41. The activities of PGG and EGCG against SARS-CoV-2 3CLpro demonstrate their inhibition of viral protease activity and highlight their therapeutic potentials for treating SARS-CoV-2 infection.
新型严重急性呼吸综合征冠状病毒（SARS-CoV-2）可在人与人之间传播，引发的冠状病毒病（COVID-19）疫情已成为全球性健康危机。SARS-CoV-2 的 3 个糜蛋白酶样蛋白酶（3CLpro）在病毒多蛋白加工中发挥着不可或缺的作用，成功抑制该蛋白酶可阻止病毒复制，从而限制病毒传播。因此，开发有效的 SARS-CoV-2 3CLpro 抑制剂来治疗 COVID-19 迫在眉睫。本研究采用荧光共振能量转移（FRET）方法，使用对应 SARS-CoV-2 3CLpro 切割序列的分子内荧光猝灭肽底物，评估 SARS-CoV-2 3CLpro 的蛋白水解活性。利用 GEMDOCK 进行分子模拟，模拟药物与 SARS-CoV-2 3CLpro 结合口袋之间的分子相互作用。本研究表明，SARS-CoV-2 3CLpro 的 V 值约为 SARS-CoV 3CLpro 的 2 倍。有趣的是，SARS-CoV-2 3CLpro 的蛋白水解活性略高于 SARS-CoV 3CLpro。同时，天然化合物 PGG 和 EGCG 对 SARS-CoV-2 3CLpro 的抑制活性明显强于对 SARS-CoV 3CLpro 的抑制活性。在分子对接中，PGG 和 EGCG 与 SARS-CoV-2 3CLpro 的底物结合口袋强烈相互作用，与多个残基形成氢键，包括催化残基 C145 和 H41。PGG 和 EGCG 对 SARS-CoV-2 3CLpro 的活性表明其抑制病毒蛋白酶活性，并突出了它们在治疗 SARS-CoV-2 感染方面的治疗潜力。
