| X-RAY DIFFRACTION |
7.5 |
289 |
The compound was dissolved in 100% DMSO to 50 mM concentration (2.30 mg + 86.2 uL DMSO). 15 uL galectin-3C (20 mg/ml in 10 mM Na phosphate buffer pH 7.4, 100 mM NaCl, 10 mM b-mercaptoethanol) were mixed with 0.5 uL compound solution. The sample was then centrifuged at 13 500 rpm for 5 min. A seed bead solution (Hampton Research) was used made from crushed apo galectin-3C crystals. The 40-fold diluted seed solution (diluted with reservoir solution similar to described below) was used to seed the crystallisation drops. The drops were set up in MRC 3-well plates and stored at 16C as follows:
200 nL galectin-3C complex + 30 nL app galectin-3C seed stock + 200 nL reservoir solution
and equilibrated against 40 uL of reservoir containing 30% PEG 4000, 0.1 M Tris/HCl pH 7.5, 0.1 M MgCl2, 7.9 mM b- mercaptoethanol.
Large crystals (0.1 - 0.2 mm) were briefly soaked in a cryoprotectant solution with the following composition:
25.5 % PEG 4000
15 % glycerol
85 mM Tris/HCl pH 7.5 85 mM MgCl2
250 mM NaSCN
8 mM b-mercaptoethanol 1 mM compound
After soaking the crystals were flash-cooled in liquid N2. |
