Figure 1
From: Non-covalent SARS-CoV-2 Mpro inhibitors developed from in silico screen hits
Development of Mpro inhibitors from in silico screening hits. (A) Graph showing the inhibitory activity of the five validated in silico screening hits tested at a final concentration of 40 μM in an in vitro protease-activity assay. After addition of the FRET substrate, fluorescence was acquired at 10 min intervals over 60 min. For each compound, the increase in fluorescence intensity was normalized to the DMSO control. GC376, a previously described Mpro inhibitor, served as a positive control. Blank, reaction omitting Mpro; RFU, relative fluorescence units. (B) Chemical structure of the five validated compounds. (C) Chemical structure of Z222979552, the most active dihydro-quinolinone compound obtained after two rounds of chemical structure similarity searches of the REAL space library of molecules. (D) Dose–response curves for compound Z222979552 examined at 0.4, 1, 3, 5, 10 and 20 μM final compound concentrations, in absence (solid lines) or presence (dashed lines) of 0.1 μg protein lysate. DMSO, GC376 and blank controls are as described above. (E) Thermal shift assay performed in the presence of DMSO or 20 μM of compounds Z222979552 or GC376. The graphs show the derivatives of the melting curves used to calculate the melting temperature of Mpro.
