ABSTRACT

A Förster resonance energy transfer (FRET)-based assay was used to screen the FDA-approved compound library against the MERS-CoV helicase, an essential enzyme for virus replication within the host cell. Five compounds inhibited the helicase activity with submicromolar potencies (IC₅₀, 0.73–1.65 µM) and ten compounds inhibited the enzyme with micromolar potencies (IC₅₀, 19.6–502 µM). The molecular operating environment (MOE) was used to dock the identified inhibitors on the MERS-CoV helicase nucleotide binding. Strong inhibitors docked well in the nucleotide-binding site and established interactions with some of the essential residues. There was a reasonable correlation between the observed IC₅₀ values and the MOE docking scores of the strong inhibitors (r ² = 0.74), indicating the ability of the in silico docking model to predict the binding of strong inhibitors. In silico docking could be a useful complementary tool used with the FRET-based assay to predict new MERS-CoV helicase inhibitors. The identified inhibitors could potentially be used in the clinical development of new antiviral treatment for MERS-CoV and other coronavirus related diseases, including coronavirus disease 2019 (COVID-19).

摘要

基于Förster共振能量转移（FRET）的分析用于筛选FDA批准的针对MERS-CoV解旋酶的化合物库，MERS-CoV解旋酶是宿主细胞内病毒复制的必需酶。五个化合物抑制与亚微摩尔效力的解旋酶活性（IC ₅₀，0.73-1.65μM）和10化合物抑制与微摩尔效力的酶（IC ₅₀，μM19.6-502）。分子操作环境（MOE）用于将已确定的抑制剂对接在MERS-CoV解旋酶核苷酸结合上。强抑制剂在核苷酸结合位点很好地对接，并与某些必需残基建立了相互作用。在观察到的IC ₅₀值与强抑制剂的MOE对接得分之间存在合理的相关性（r ²  = 0.74），表明计算机对接模型预测强抑制剂结合的能力。计算机对接可能是与基于FRET的测定法一起用于预测新的MERS-CoV解旋酶抑制剂的有用补充工具。鉴定出的抑制剂有可能用于MERS-CoV和其他冠状病毒相关疾病（包括2019年冠状病毒疾病）（COVID-19）的新抗病毒治疗的临床开发中。