Figure 5
From: Structural and functional characterization of MERS coronavirus papain-like protease
Proteolytic and DUB activity assay of MERS-CoV PLproand its mutants. Panel (A) shows the plot of initial velocities versus the concentration of peptidyl substrate, Dabcyl-FRLKGGAPIKGV-Edans. The concentration of the wild-type MERS-CoV PLpro (by circles), the L105W (by triangles) and P162L mutants (by squares) was 1, 0.1 and 10 μM, respectively. The line represented the best-fit results according to the Michaelis-Menten equation (Eq. 1). The kinetic parameters derived are shown in Table 2. (B) DUB activity analysis. The fluorogenic substrate Ub-AFC (1 μM) was used as the substrate. For comparison, both DUB activity of SARS-CoV and MERS-CoV PLpro was tested. The protein concentration was 0.17 μM. Besides, the inhibition of MERS-CoV PLpro by 10–50 mM EDTA or 50 μM Zn2+ were also clarified.