| X-RAY DIFFRACTION |
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293 |
CamKII S3-K301, in 20mM imidazole pH 8.5, 0.3M sodium chloride, 5mM TCEP, was concentrated to 36 mg/ml and flash frozen in liquid nitrogen for long term storage at -80 C in 10 uL aliquots. The protein was thawed and diluted down to 12 mg/mL in the same buffer just prior to crystallization experiments. Sitting drop vapor diffusion droplets were assembled with 250 nL of 12 mg/mL CamKII, 0.6 mM inhibitor and 250 nL of reservoir solution 24% peg 3350, 0.2 M ammonium tartrate, 0.1 M arginine. Flat crystal plates (typically 0.03 mm x 0.2 mm x 0.4 mm in size) grew in 4-7 days at 20 C. A crystal seed suspension was prepared with ten crushed crystals combined into 100 uL of reservoir solution and stored at -80 C. A thirty fold seed dilution was prepared in the same solution for addition to protein droplets in a 1 to 1 volume ratio to enhance crystallization of difficult to crystallize inhibitors. |
