Figure 3

PL^proSARS displays a higher catalytic efficiency than PL^proCoV2 toward Ub-AMC. (a,b) Progress curves for the hydrolysis of Ub-AMC by PL^proSARS (a) and PL^proCoV2 (b). The concentrations of Ub-AMC are shown in the legend in nM, PL^proSARS and PL^proCoV2 were10 nM. (c) Four steps of the Approximate Bayesian Computation (ABC) for calculating values of kinetic constants k_cat and K_M. (d,e) A comparison of measurements (in blue) and solutions of the Michaelis–Menten model for given parameters of enzymatic constants found by the ABC method (in red) for PL^proSARS (d) and PL^proCoV2 (e) at 500 nM substrate concentration (k_cat and K_M are expressed in s⁻¹ and μM, respectively). (f) The kinetic data (k_cat, K_M, k_cat/K_M) for the Ub-AMC substrate of PL^proSARS and PL^proCoV2.