ConBr was purified as described by Cavada et al. [13] and solubilized in deionized water at a concentration of 12.5 mg ml?1 in all crystallization experiments. Crystallization conditions for ConBr were screened using the hanging-drop vapor Lapatinib method with a commercially available crystallization solution (Hampton Research Screens I and II, Hampton Research, Riverside, CA, USA) at room temperature (293 K). Drops were prepared by mixing 2.0 μL sample solution and 2.0 μL reservoir solution, followed by equilibration against 300 μL reservoir solution [14]. Small crystals were obtained using crystallization condition No. 32 from the Crystal Screen II kit (0.1 M sodium chloride, 0.1 M Hepes, pH 7.5, and 1.6 M ammonium sulfate). The initial crystallization condition was optimized by increasing the concentration of sodium chloride, ammonium sulfate and pH. The best crystals were obtained with 0.2 M NaCl, 0.1 M Hepes, pH 8.5, and 1.8 M ammonium sulfate. Crystals suitable for X-ray diffraction grew in one week to maximum dimensions of approximately 0.4 × 0.5 × 0.4 mm.