Membrane Protein Crystallization Screen
Analytic Crystallizer Kit (1.7 ML Crystallization Screen / 150 µl Optimizer PreScreen)
The Analytic Crystallizer kit comprises a two-step method for optimal crystallization screening of detergent-solubilized integral membrane proteins (IMPs) in a manner independent of detergent identity. The kit includes a solubility prescreen (Optimizer) that is used to determine the appropriate protein concentration for use with the crystallization screen, which is then followed by the 96-condition crystallization screen (Crystallizer). The use of Optimizer allows the experimenter to reduce the amount of crystallization conditions to be screened in the first screening pass and to increase the likelihood of crystallization success. The result of coupling the Optimizer and Crystallizer solutions sets is the assurance that the majority of the crystallization screen solutions will result in supersaturation of the protein without excessive non-crystalline precipitation.
The conditions for Crystallizer have been formulated to avoid redundancy and maximize coverage of crystallization space. Precipitants and salts were mined from the conditions most frequently used in successful membrane protein crystallization experiments, as available in the Membrane Protein Data Bank. Also sampled are six buffers ranging from pH 4.5 to 9.5 and 18 distinct salts.
The formulations provided here have been further tuned to render the screen detergent-independent, meaning that the precipitant and salt concentrations have been selected to minimize phase separation that typically occurs for solutions containing high concentrations of detergents that are typically used to maintain the solubility of membrane proteins.