| X-RAY DIFFRACTION |
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296 |
Mb(H64G,V68A) at 2.5 mM in 20 mM Tris-HCl pH 8.4, 1 mM EDTA, was mixed with an equal volume of reservoir solution (200 mM Tris-HCl pH 8.9 and 2.4 M ammonium sulfate) to perform hanging-drop vapor diffusion crystallization. A crystal was transferred from the drop it was grown in to another 4 uL drop containing well solution with the addition of 10% glycerol. The drop was overlaid with 4 uL mineral oil. A micropipette tip was dipped in sodium dithionite powder and the tip was then slowly submerged into the drop to allow the dithionite crystals to be released. 1 uL of benzyl diazoketone at 500 mM (dissolved in isopropanol) was then added to the drop for a final concentration of 100 mM, then incubated for an additional 22.5 minutes. The crystal was then looped and flash-frozen in liquid nitrogen. |
