   3.1.1.41 | purified recombinant selenomethionine-substituted and wild-type enzyme in complex with covalently bound phenylmethylsulfonyl fluoride and paraoxon, hanging drop vapour diffusion method, for selenomethionine-substituted enzyme: mixing of 500 nl of 15 mg/ml protein in 20 mM Tris pH 7.9, 150 mM NaCl, 0.25 mM TCEP, in presence or absence of inhibitors, with 500 nl of reservoir solution containing 20% w/v PEG-3000, 0.1 M HEPES pH 7.5, 0.2 M NaCl, and equilibration against 0.25 ml of reservoir solution, for wild-type enzyme: mixing of 100 nl of 22.8 mg/ml protein in 20 mM Tris pH 7.9, 150 mM NaCl, 0.25 mM TCEP, in presence or absence of inhibitors, with 100 nl of reservoir solution containing 0.2 M calcium acetate hydrate, 20% w/v PEG 3350, pH 7.3, and equilibration against 0.06 ml of reservoir solution, 20°C, X-ray diffraction structure determination and analysis at 2.4 A and 2.1 A resolution, respectively, molecular replacement, structure modeling |
