Figure ED8. In vitro protease assay on SARS-CoV-2 papain-like protease (PLpro) and main protease (Mpro).
Purified SARS-CoV-2 Mpro (A) and SARS-CoV-2 PLpro (B) enzymes were incubated with varying concentrations of each compound, ranging from 1 to 50 μM. Activity of purified SARS-CoV-2 Mpro and SARS-CoV-2 PLpro enzymes was measured using the UIVT-3 peptide substrate (HiLyte Fluor488TM-ESATLQSGLRKAK-QXL520TM-NH2) and the peptide substrate Arg-Leu-Arg-Gly-Gly-AMC (RLRGG-AMC) respectively. Enzyme activity in the absence (zero percent inhibition control) and presence of compounds were used to calculate the percent inhibition at each compound concentration. Data are presented as mean ±SD for n=3 independent experiments.