Except remdesivir, no specific antivirals for SARS-CoV-2 infection are currently available. Here, we characterize two small-molecule-compounds, named GRL-1720 and 5h, containing an indoline and indole moiety, respectively, which target the SARS-CoV-2 main protease (M pro ). We use VeroE6 cell-based assays with RNA-qPCR, cytopathic assays, and immunocytochemistry and show both compounds to block the infectivity of SARS-CoV-2 with EC 50 values of 15 ± 4 and 4.2 ± 0.7 μM for GRL-1720 and 5h, respectively. Remdesivir permitted viral breakthrough at high concentrations; however, compound 5h completely blocks SARS-CoV-2 infection in vitro without viral breakthrough or detectable cytotoxicity. Combination of 5h and remdesivir exhibits synergism against SARS-CoV-2. Additional X-ray structural analysis show that 5h forms a covalent bond with M pro and makes polar interactions with multiple active site amino acid residues. The present data suggest that 5h might serve as a lead M pro inhibitor for the development of therapeutics for SARS-CoV-2 infection. Here, using in vitro assays and structural analysis, the authors characterize the anti-SARS-CoV-2 properties of two small molcules, showing these to bind and target the virus main protease (M pro ), and to exhibit a synergistic antiviral effect when combined with remdesivir in vitro.
【저자키워드】 SARS-CoV-2, Antimicrobials, 【초록키워드】 Antiviral, Therapeutics, SARS-COV-2 infection, Remdesivir, cytotoxicity, protease, in vitro, virus, anti-SARS-CoV-2, SARS-CoV-2 main protease, Antiviral effect, In vitro assay, X-ray, Viral, inhibitor, Amino acid, Structural analysis, lead, active site, indole, Compound, M pro, amino acid residues, covalent bond, immunocytochemistry, indoline, polar interactions, synergism, cytopathic, block, synergistic, assays, detectable, form, exhibit, polar interaction, the SARS-CoV-2, 【제목키워드】 protease, virus replication, block, inhibit,