Figure 9.

(a) Free energy profile along the MFEP obtained from the S236-W3-S181 mechanism. (b) Transition structure in which proton transfers along the proton wire $\mathrm{W}1\to \text{Ser}236\to \mathrm{W}3\to \mathrm{S}181\to {\mathrm{P}}_{\gamma }{\mathrm{O}}_3^{-}$.