Electrostatics in Macromolecular Solutions - Food Colloids: Self-Assembly and Material Science - page 144

Figure 8 Capacitance of proteins as a function of pH. (a) Calbindin D 9k (pI E 4.2): the
thick solid curve is from MC simulation, while the thin solid line is the ideal
capacitance calculated from Equation (21). (b) Hisactophilin (pI ¼ 7.3)
to charge-dipole and/or dipole-dipole interactions, but they do not seem
to be important in the present case: the main contribution to the interaction-
free energy comes from the induced charges. This is further demonstrated in
Figure 9(b), where one can follow how the net charge of calbindin goes from
around +1.4 at infinite separation to around 0.5 at contact. We will return to
this issue when discussing protein-polyelectrolyte complexation.