Crystallization of a globular protein in lipid cubic phase.

We studied the crystallization of a globular protein, lysozyme, in the cubic phase of the lipid mono-olein. The solubility of lysozyme in salt solution decreased by a factor of approximately 4 when confined in cubic phase. Monte Carlo simulations and calculations show that this can be explained by the confinement of lysozyme molecules to the narrow water cells in the cubic phase.