This correction is shown in Fig. for all four proteins studied here and for the background protein dielectric constant ε ∞ = 4 and salt concentration n 0 = 100 mM. The correction to the dielectric constant is very large and exceeds ε p 10 for most of the pH range studied. This trend persists even at higher values of ε ∞ or lower values of n 0 (Fig. in the SI).