Mesoscopic surfactant organization and membrane protein crystallization

The paucity of detailed X-ray crystallographic structures of integral membr ane proteins arises from substantive technical obstacles in the overexpress ion of multimilligram quantities of protein, and in the crystallization of purified protein-detergent complexes (PDCs). With rare exception, crystal c ontacts within the lattice are mediated by protein-protein interaction, and the detergent surrounding the protein behaves as a disordered solvent. The addition and use of surfactants that display mesoscopic self-assembly beha vior in membrane protein crystallization experiments presents a novel alter native strategy. Well-ordered crystals of the water channel human aquaporin -1 (hAQP1) that diffract to 4 Angstrom resolution have been obtained with t his approach.