FIG 11.

The small molecules 5705213 and 7402683 are more specific inhibitors of CatL than CatB. The small molecules were tested in different concentrations (50 to 200 μM) for inhibition of CatB activity in an in vitro activity assay (Anaspec Inc.) The percentages of inhibition were calculated for each inhibitor. The inhibition of CatB activity was compared to the inhibition of CatL activity against SARS-CoV-S-derived peptide in the presence of a 50 to 200 μM concentration of the small molecules 5705213 and 7402683. The CatL inhibitor III and CatB inhibitor were used as controls in the CatL and CatB assays, respectively. The experiment was performed in triplicates and repeated thrice with similar results. Error bars represent SD from a representative experiment.