The correlation statistics of the 4EWO simulations with the Asp32 H , Asp228 -protonation state are reported in Table 3 and the plot of predicted versus experimental affinities is depicted in Fig. . Also, Fig. shows the distribution of the MM-GBSA scores for the two protonation states. Overall, the MM-GBSA scores were lower for the single protonated aspartyl dyad compared to the double protonated, indicating that the binding pose is more stable for the single protonation state. The Kendall τ improved by about one standard deviation, confirming that the Asp32 H , Asp228 - form is more adequate than modeling both Asp as protonated.