Journal: Journal of Medicinal Chemistry

Article Title: 3CL Protease Inhibitors with an Electrophilic Arylketone Moiety as Anti-SARS-CoV-2 Agents

doi: 10.1021/acs.jmedchem.1c00665

Figure Lengend Snippet: 3CL protease inhibitors for SARS-CoV-1 with electrophilic arylketone warhead. (A) Structures of 3CL pro inhibitors 1 , SH-5, YH-53, and YH-71. SH-5 contains a tripeptide scaffold with a warhead and a carbamoyl unit at P4. YH-53 and YH-71 consist of a dipeptide scaffold with a warhead and a heteroaromatic unit at P3. (B) Proposed mechanism of inhibition by SH-5. Once SH-5 is bound to the enzyme, the active site Cys145 of 3CL pro attacks the ketone of SH-5 to afford a reversible covalent bond. The hemithioketal intermediate would then be stabilized by an oxyanion hole.

Article Snippet: The Lineweaver–Burk plot and the global data fitting for competitive inhibition were performed with GraphPad Prism 8.0.

Techniques: Inhibition

Journal: Journal of Medicinal Chemistry

Article Title: 3CL Protease Inhibitors with an Electrophilic Arylketone Moiety as Anti-SARS-CoV-2 Agents

doi: 10.1021/acs.jmedchem.1c00665

Figure Lengend Snippet: SARS-CoV-2 3CL pro inhibitory assay. (A) Concentration-dependent inhibition of SARS-CoV-2 3CL pro by SH-5, YH-53 and YH-71. Reactions were monitored for 10 min. Data points represent mean values ± SEM from three independent experiments. K i values were calculated using the Cheng–Prusoff equation and are noted in Figure . The K m value of the substrate was 48.4 μM. (B) Lineweaver–Burk plot for SH-5 inhibition of SARS-CoV-2 3CL pro at 15, 30, 45, 60, and 75 μM of fluorogenic substrate and 0, 10, 20, 30, 40, and 50 nM of the inhibitor SH-5. Three independent experiments were performed, and reactions were monitored for 10 min. The common intercept on the ordinate indicates a competitive inhibition type. (C) Global fit of kinetic data from (B) for competitive enzyme inhibition. The best fit value of K i 19.8 ± 2.3 nM was in the same range as the value calculated by the Cheng–Prusoff equation (see Figure ).

Article Snippet: The Lineweaver–Burk plot and the global data fitting for competitive inhibition were performed with GraphPad Prism 8.0.

Techniques: Concentration Assay, Inhibition, Enzyme Inhibition Assay