A phenomenological model for lipid-protein bilayers with critical mixing.

A Landau expansion of free energy in terms of area/lipid has been used to obtain protein-lipid phase diagrams with critical mixing and a maximum phase separation concentration. Simulations using this model indicate that differential scanning calorimetry scan shapes and transition enthalpies observed for lipid-synthetic peptide mixtures are consistent with this type of phase diagram. The critical mixing point and the homogeneous mixture critical point are distinguished.