Crystallization of a polar protein and small molecules from the aqueous compartment of lipidic cubic phases

Lipidic cubic phases allow crystallization of both water-soluble compounds (salts and hydrophilic proteins) and hydrophobic molecules. Unlike the crystallization of the membrane protein bacteriorhodopsin, the nucleation and growth of sodium chloride, glycine and lysozyme crystals are independent of the type of cubic phase and the packing arrangements of the lipidic compartments. The crystals obtained diffracted X-rays to better than 1.5 Angstrom (small molecules) and 2.0 Angstrom (lysozyme). Crystallization in lipidic cubic phases is assisted by the resistance of these matrices toward doping with a wide variety of detergents, precipitants, and additives.