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Beta-lytic protease from Myxobacter 495 was crystallized by dialysis with 1 m-sodium chloride and 0.1 m-sodium citrate (pH 5.95). The crystals were rhombic prisms with space group P212121 and unit cell parameters a = 54.1, b = 99.6 and c = 53.9 A?. Considerations of the cell volume and molecular weight indicate two molecules of beta-lytic protease in the asymmetric unit.  相似文献   

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Crystals of actinidin, a thiol protease from the fruit of Actinidia chinensis, which are suitable for high-resolution X-ray diffraction studies, have been obtained. The space-group is P212121, with a = 78.1 A?, 6 = 81.2 A? and c = 33.0 A?. The asymmetric unit contains one molecule, of molecular weight about 26,000.  相似文献   

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Preliminary crystallographic data for transketolase from yeast   总被引:1,自引:0,他引:1  
Crystals of the vitamin B1-dependent enzyme transketolase from baker's yeast have been grown from the apo- and the holoform of the enzyme, using PEG as precipitant. The crystals are orthorhombic, space group P2(1)2(1)2(1) with cell constants a = 76.3 A, b = 114.2 A, and c = 163.5 A. The crystals are stable in the x-ray beam and diffract to at least 2.2 A on a conventional x-ray source. The enzyme is a dimer of identical subunits, and a Vm value of 2.2 A/dalton indicates that the asymmetric unit contains a dimer. Rotation function calculations using native data (10-5 A) revealed a local 2-fold rotation axis with phi = 0 degree and omega = 20 degrees.  相似文献   

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Preliminary crystallographic data on human lysozyme   总被引:1,自引:0,他引:1  
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Superoxide dismutase from spinach leaves was salted out with ammonium sulphate. The resulting crystals were monoclinic, space group C2, with unit cell dimensions a = 166.2 A?, b = 46.1 A?, c = 85.6 A? and β = 99.3 °. Considerations of cell volume and protein molecular weight indicated two molecules of superoxide dismutase in the asymmetric unit.  相似文献   

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Two closely related crystal forms of dimeric cytochrome c5 from Azotobacter rinelandii have been grown. The crystals belong to space groups (C2 with a = 45·0, b = 38·4, c = 41·3 A? and β = 101 ° 0′; and C1 (a centered triclinic cell) with a = 46·0, b = 37·6, c = 49·4 A?, α = 87 ° 20′, β = 96 ° 40′ and γ = 90 ° 0′. In C2 the 24,000 molecular weight dimer lies on a Crystallographic 2-fold axis; in C1 the entire dimer occupies the asymmetric unit.  相似文献   

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Glycolate oxidase, an enzyme that plays an important role in photorespiration in plants, has been purificant from spinach and crystallized in two different crystal forms. Form A which was obtained with tertiary butanol as precipitating agent belongs to space group I 422 with unit cell dimensions a = b = 148.1 A and c = 134.9 A. This form diffracts to high resolution and will be used for further crystallographic studies. Form B is also tetragonal, space group P42212, with cell dimensions a = b = 145.4 A and c = 104.2 A. This form was obtained from ammonium sulfate precipitations. Sodium dodecyl sulfate polyacrylamide gel electrophoresis shows that the enzyme is built up from subunits of molecular weight 37,000. The asymmetric units of both crystal forms contain at least two such subunits.  相似文献   

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The β-lactamase (penicillinase) from Escherichia coli W3310 has been crystallized from 25% saturated ammonium sulfate solution at pH 6.9. An X-ray examination of the monoclinic crystals shows the space group is C2, with unit cell dimensions a = 47.2 A?, b = 76.9 A?, c = 73.3 A? and β = 98.6°. With Z = 4 and the molecular weight = 22,000 (Melling &; Scott, 1972), the Å3/dalton ratio is 2.98. The crystals are suitable for structure analysis to at least 2.4 Å resolution.  相似文献   

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Lactoglobulin isolated from Italian buffalo milk has been crystallized in two different forms. Crystals of type I have been grown at pH 3.5 and belong to space group P63; the unit cell dimensions are a = b = 67 A?, c = 142 A?, and accordingly the asymmetric unit contains one dimer of molecular weight 36,000. Type II crystals, grown at pH 8.5, have only one monomer per asymmetric unit; the space group is P3121 (or enantiomorph) and the unit cell edges are: a = b = 54.4 A?, c = 113.2 A?. The crystals of the trigonal form show low radiation damage and are suitable for a structural investigation.  相似文献   

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A well characterized soybean protease inhibitor, the Bowman-Birk inhibitor, has been crystallized at room temperature in the presence of polyethylene glycol 4000 by vapor diffusion against an ammonium sulfate solution containing 2-methyl-2,4-pentanediol. An x-ray diffraction study reveals that the inhibitor crystallizes in a hexagonal unit cell of symmetry P6122 (or P6522) and dimensions a = b = 91.36(2) A and c = 63.92(2) A. Each of the 12 asymmetric units contains 2 molecules of molecular weight 8000. The crystal, which diffracts barely to 3-A spacings, is fairly stable to x-irradiation and has a solvent content of approximately 52% by volume.  相似文献   

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Crystals of lysozyme from Streptomyces erythraeus are orthorhombic, space group P212121 with unit cell dimensions: a = 50.01 A?, b = 61.98 A? and c = 67.85 A?; and one molecule, of molecular weight about 18,500, per asymmetric unit.  相似文献   

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The serotype B of exfoliative toxin, isolated from Staphylococcus aureus, strain TC 142, has been crystallized. The monoclinic crystals belong to space group P21, with a = 55.9 A?, b = 107.9 A?, c = 42.8 A?, and β = 90.9 °. The asymmetric unit contains two molecules of molecular weight 30,000.  相似文献   

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Single crystals of adenylosuccinate synthetase, an essential component of purine biosynthesis, extracted from rabbit skeletal muscle were prepared as suitable specimens for X-ray structure analysis. The crystal belongs to the space group P43212 or P41212 with unit cell dimensions a = b = 71.2 A?, c = 194.8 A?. The asymmetric unit contains one protein molecule of 54,000 molecular weight.  相似文献   

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