Fig 4. Characterization of activity and inhibitor binding properties of recombinant SARS-CoV-2 PLpro variants.

Assay conditions: [E]=100 nM, [S]=10 μM. (A) Determination of activity of the PLpro mutants toward tetrapeptide fluorogenic substrate. Experiment was repeated at least two times. (B) IC50 determination for variants that possessed enzymatic activity of GRL-0617 and S43 inhibitors. Enzyme was incubated in assay buffer for 10’ followed by enzyme incubation with inhibitor for 30’ prior to the measurement. Measurements were performed three times.