FIG. 5.

TGEV PL1^pro in vitro activity assays. The hydrolysis of ubiquitin-AMC (squares) and cleavage of DABCYL-MYNKMGGGDKTVSF(E-EDANS)-amide (triangles) were measured at different substrate concentrations (0.2, 0.3, 0.4, 0.5, 0.6. 0.7, 0.8, and 1 μM in the case of the Ub-AMC and 10, 20, 30, 40, and 50 μM in the case of the FRET peptide). The TGEV PL1^pro concentration was 0.5 μM. For both experiments the initial velocities were calculated and data were fit to the equation (see text), which allowed the determination of the k_app value. For clarity, a logarithmic scale was used for the horizontal axis.