engleski

Protein Measurement on Laboratory Powder Diffractometer

Han egg white lysozyme has been dissolved into 0.1 M sodium acetate-acetic buffer at pH 4.8 to a final concentration of 60mg/ml. This has been mixed with a second solution of 8% sodium chloride in the same 0.1 M puffer and kept at 22oC. Tetragonal crystals of various sizes smaller than 150 μ m were obtained after 46 hours. These crystals were removed from the mother-liquor using a pipette, and placed into a 0, 5mm glass capillary. The crystals were manually compacted and the remaining mother-liquor has been removed. The sample was measured on an X'Pert PRO Multi-Purpose Diffractometer (MPD), configured in transmission geometry with a focusing mirror on the incident beam side and an X'Celerator detector on the diffracted beam side. The sample was measured at room temperature with a scan range of 1-45o (2A), a step size of 0.004o and a total scanning time of 40 hours. The raw data were indexed by the DICVOL program, integrated into the HighScore Plus software suite, giving a tetragonal cell with parameters: a= 79.58Å ; , c=38.09Å ; . Both Le Bail and Pawley fit showed good agreement.

lysozyme; transmission geometry

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