Figure 2: Screening of known protease inhibitors against SARS-CoV-2 Mpro using the FRET assay.
20 μM of compounds (26 was tested at 2 μM) was pre-incubated with 100 nM of SARS-CoV-2 Mpro for 30 minutes at 30 °C, then 10 μM FRET substrate was added to reaction mixture to initiate the reaction. The reaction was monitored for 2 hours. The initial velocity was calculated by linear regression using the data points from the first 15 minutes of the reaction. The calculated initial velocity with each compound was normalized to DMSO control. The results are average ± standard deviation of two repeats.