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MEMBRANE PROTEIN CRYSTALLIZATION SCREEN home > about > HTS services > membrane protein screen
The effect of temperature on detergent phase partitioning. The phase separation for a 0.5% tetraethylene glycol monooctylether, PEG 4000 and LiCl combination was recorded 7 days post setup at 20ºC, followed by transferring the plate to 4ºC for an additional 7 days so that the effect of temperature on phase partitioning could be monitored (Koszelak-Rosenblum et al., 2009).

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Structural characterization of membrane proteins is a vital component in efforts to understand the processes behind many disease states.  Crystallization of a membrane protein is hampered by the requirement of detergent, which is used to extract the protein from the lipid bilayer to form a protein-detergent complex (PDC). Hartmut Michel and other early pioneers of membrane protein crystallization research observed the formation of crystals near the phase boundary of the detergent used to form the PDC.  Understanding the variables associated with detergent phase behavior and crystallogenesis enables their rational modulation.

We have generated chemically diverse phase boundary data utilizing dye-based phase partitioning and eleven detergents commonly used to crystallize membrane proteins. The resulting data have been used to guide the formulation of a 1536-cocktail crystallization screen for membrane proteins.  The experimentally derived phase boundary data and the 1536-well membrane screen are now available through the high-throughput crystallization facility located at the Hauptman-Woodward Institute. The phase boundary data has also been packaged into an interactive Excel spreadsheet (SlickSpot.xls) that allows investigators to formulate grid screens near a given phase boundary for a particular detergent.

The membrane protein crystallization screen is now available for use by the greater structural biology community.  At this point, there is no charge for academics to utilize the screening service for membrane proteins. (Industrial users should contact Mike Malkowski [716-898-8624] for pricing information.) However, only membrane-associated proteins will be accepted for the membrane screen, and information about detergents used for solubilization and for purification will be required on the submission form.  Screens are set up the first Thursday of each month and require 500 microliters of protein sample.  Every effort will be made to accommodate investigator requests as quickly as possible. Users of the membrane screen can specify whether their plates are to be incubated at 23°C, 14°C or 4°C.

If the membrane protein crystallization screen assists you in identifying initial crystallization conditions, please cite the reference below so that we may track the use and success of the screen and the HTS facility:

Koszelak-Rosenblum, M., Krol, A., Mozumdar, N., Wunsch, K., Ferin, A., Cook, E., Veatch, C. K., Nagel, R., Luft, J. R., DeTitta, G. T & Malkowski, M. G. (2009). Determination and application of empirically derived detergent phase boundaries to effectively crystallize membrane proteins. Protein Science 18, 1828-1839.  [Pub Med ID: 19554626]