We determine the phase diagrams of two widely studied protein solutions, namely, lysozyme and gamma-crystallin in water and added salt, within a short-range, pair-potential representation of macroparticle interactions. A one-parameter fit of the model is performed on the basis of static or dynamic light scattering and self-interaction chromatography data. Demixing and crystallization curves, as calculated through numerical approaches, turn out to be in good agreement with experimental protein-rich-protein-poor and solubility envelopes. Our findings highlight the minimal assumptions about the nature of the microscopic potential allowing a satisfactory reproduction of the phase-diagrarn topology of globular protein solutions.