4.4.1.20 comparative molecular dynamic analysis. Residue Ser36 upon phosphorylation will pull the first luminal loop of LTC4S toward the neighboring subunit of the functional homotrimer, thereby forming hydrogen bonds with catalytic residue Arg104 in the adjacent subunit. The phosphorylation-induced interaction leads to a reduction of the catalytic activity 748212 4.4.1.20 its apo and GSH-complexed forms to 2.00 and 2.15 A resolution, using the sitting drop vapour diffusion technique 682094 4.4.1.20 large number of parameters are important in obtaining big and well-ordered 2D crystals of LTC4S. Order can be induced by a combination of dividing/selecting fractions during the purification as well as a low lipid-to-protein ratio. To obtain a favorable diameter, salt (optimal: 50 mM), temperature (optimal: 23-24°C), glycerol (optimal: 20%), and initial detergent concentration (optimal: 1%) have to be controlled. Several crystal forms can be grown, namely the plane group symmetries of p2, p3, p312, and two different unit cell sizes of plane group symmetry p321 with unit cell dimensions of a = b = 73.4 A, c = 120 and the second p321 type with larger unit cell size of a = b = 83.0 A, c = 120. Four transmembrane alpha-helices present, to 7.5 A resolution 709717 4.4.1.20 LTC4S crystallized with glutathione, The structure is determined by the multiwavelength anomalous diffraction method by using the diffraction images from native LTC4S and a selenomethionine-substituted Leu121Met mutant 682093 4.4.1.20 molecular docking of inhibitors 2-benzoyl-5-[5-[(4-chlorophenyl)(methyl)amino]pyridine-2-carbonyl]benzoic acid, 5-[5-[(4-chlorophenyl)(methyl)amino]pyridine-2-carbonyl]-2-(4-methoxybenzoyl)benzoic acid, 5-[5-[(4-chlorophenyl)(cyclopropylmethyl)amino]pyridine-2-carbonyl]-2-(4-methoxybenzoyl)benzoic acid. Inhibitors interact with catalytic residues R104 and R31 748456 4.4.1.20 purified enzyme in apoform or in complex with either one of three product analogues, S-hexyl-, 4-phenyl-butyl-, and 2-hydroxy-4-phenyl-butyl-glutathione, sitting drop vapor diffusion, mixing of 0.001 ml of 3.5 mg/ml protein solution containing 1 mM GSH with 0.001 ml of reservoir solution containing 1.8-2.2 M NH4SO4, 0.2 M NaCl, and 0.1 M sodium cacodylate, pH 6.1-6.8, 1-4 days, room temperature, soaking in 1 mM ligand solutions, X-ray diffraction structure determination and analysis at 2.4-3.2 A resolution 730061 4.4.1.20 purified enzyme in apoform or in complex with substrate glutathione or product analogue S-hexyl-GSH, mixing of 0.001 ml of 3.5 mg/ml protein in 0.03% w/v DDM w/v, 20 mM Tris pH 8.0, 100 mM NaCl, and 0.5 mM TCEP, with or without 1 mM GSH, with 0.001 ml of reservoir solution containing 1.8-2.2 M NH4SO4, 0.2 M NaCl and 0.1 M Na cacodylate pH 6.1-6.8, for S-hexyl GSH-enzyme crystals, S-hexyl GSH is added to mother liquor and soaking of apo-crystals, X-ray diffraction structure determination and analysis at 2.65-2.7 A resolution 730788 4.4.1.20 resolution of 4.5 A 666938 4.4.1.20 sitting drop vapour diffusion method using the MbClass and MbClass II suites 694966 4.4.1.20 the interaction of residue R104 with the thiol group of GSH reduces its pKa to allow formation of a thiolate anion and subsequent nucleophilic attack at C6 of LTA4.Crystal structure of mutant R31Q at 2.1 A reveals a Q31 side chain pointing away from the active site 715569 4.4.1.20 wild-type to 1.9 A resolution, space group F23. Mutants R31A and R104A, space groups F23 and C222, respectively. The architecture for GSH binding is conserved. The GSH binding site is a V-shaped cleft at each intermonomer interface in the LTC4S trimer, and nine amino acid residues directly participate in the GSH binding. Residue R30 multiply binds the carboxyl group of the gamma-glutamyl moiety, and R104 interacts with both the thiol group and the carbonyl group of the cysteinyl moiety of GSH. The side chain of R31 is flexible in the crystal structure 715600 4.4.1.20 X-ray structure refined to 2.15 A resolution 709128