Crystallization of integral membrane proteins.

Over the last 20 years, the use of X-ray crystallography has become a viable technique for the structure determination of integral membrane proteins. However, standard crystallizaton protocols must be modified to account for difficulties involved in handling membrane proteins, which arise primarily from having detergent present. This unit provides protocols that can be used to crystallize a purified membrane protein, including detergent exchange, sample concentration, initial screening using a crystallization robot, and finally, optimization of crystallization conditions to obtain diffraction-quality crystals. These protocols were established for outer membrane proteins, but can be used for inner membrane proteins as well. Advice on alternative protocols, detergent selection, and optimization of crystallization conditions is provided.