The changes in the dipole moment of hisactophilin as a function of pH are shown in Fig. , again both in presence and in absence of CR. Figure also shows the changes in the square root of dipole moment fluctuations as a function of pH. Here, the fluctuations are often maximal when the dipole moment is minimal and vice versa, although this does not seem to be a general rule. Another observation, stemming directly from our theoretical calculations, is that the pH dependence of the dipole moment fluctuations is essentially the same as the dependence of total charge fluctuations, which can be seen from comparing panels (a) and (b) of Fig. . This is a simple consequence of the fact that the total charge as well as the total dipole moment fluctuations depend on the same proton occupancy correlator δq k δq t (see the examples in Fig. and Figs. S2 and S3 in the SI), which displays positive values for the diagonal terms (self energy) and negative values (anticorrelation) for off-diagonal terms. The intermittency in the diagonal components is due to full neutralization of some charged groups at those solution conditions. These observations are characteristic of all four proteins studied, which can be seen from Figs. S4 and S5 in the SI.