Figure 2.
Enzymatic assay of SARS-CoV-2 Mpro and PLpro, EV-A71 and EV-D68 2Apro and 3Cpro against inhibitors investigated in this study. (A) SARS-CoV-2 Mpro; (B) SARS-CoV-2 PLPro; (C) EV-A71 2Apro; (D) EV-A71 3Cpro; (E) EV-D68 2Apro; and (F) EV-D68 3Cpro. Protease was pre-incubated in their corresponding reaction buffer as described in the method section with various concentrations of protease inhibitors in the presence of 4 mM DTT or in the absence of DTT at 30 °C for 30 min. The enzymatic reaction was initiated by adding the corresponding FRET substrate. The efficacy of these protease inhibitors in the presence of 4 mM DTT or in the absence of DTT was evaluated with a four parameters dose response curve function in prism 8 as described in the method section.