Comparison
of calculated and experimental activation free energies (kcal mol–1) for the hydrolysis of DFP by wild-type and mutant
forms of DFPase. Considered in this work are general-base and nucleophilic
substitution mechanisms, respectively, as illustrated in Figure 2. “QUAD”
denotes an E73D/Y144A/R146A/T195M quadruple mutant. The corresponding
raw data are shown in Table S2. The data
shown are average values and standard error of the mean over 30 individual
EVB trajectories per system, as described in the Methodology section. The chart on the left depicts values
relative to the reference reaction in solution, whereas the chart
on the right shows values relative to WT enzyme. The Spearman rank
coefficient (rs) and root-mean-square
errors (RMSE) of the calculated effects of mutations are shown in
the top-right corner. The experimental data was obtained from refs (46), (50), and (75). Note that in the case
of the N175D and H287A variants, only relative specific activities
(s.a.) were available; thus, the reported ΔG⧧exp values are approximate (see Table S2). Finally, the green line in the panel
on the right illustrates perfect agreement between calculated and
experimental values to give a visual guide as to how much each calculated
value deviates from this.