Specific ion effects and the phase diagram of lysozyme

The phase diagram for lysozyme is calculated for the precipitant salt NaCl using a potential of mean force that takes into account contributions from ion-dispersion forces (J. Phys. Chem. B 110 24757). In contrast to the perturbation theory calculation, we find that the lysozyme phase diagram with NaCl has a metastable fluid-fluid coexistence curve. We also compare our predicted phase diagram with experimental results in the case of NaCl. Our results suggest that a refined version of the current model is necessary to account quantitatively for the experimental phase diagram of lysozyme.