Membrane crystallization of macromolecular solutions

Crystal growth is the critical step in determining the protein X-ray crystal structure. Hundreds, or even thousands, of crystallization trials must often be performed on a target macromolecule and, unfortunately, less than 1% of them typically yield promising results. Many macromolecules are reluctant to crystallize and, usually, their crystalline arrangement is not good enough to provide diffraction data at a resolution sufficient to establish structure-function correlation. The history of macromolecular crystallization emphasizes the importance of new observations and ideas that are useful in initiating more systematic studies using novel techniques and creative approaches. On this basis an innovative methodology, the membrane crystallization, has been introduced in order to promote the formation of macromolecular crystals. Lysozyme crystals, produced by removing the solvent (in vapour phase) from the protein solution by using microporous hydrophobic membrnaes, showed a good structural quality suitable for successive X-ray diffraction analysis.