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1.
Single crystals of a bovine neurophysin II-oxytocin complex have been obtained using (NH4)2SO4 as the precipitating agent. The crystals diffract to at least 2.7 A resolution, belong to Laue group 4/mmm and exhibit systematic absences consistent with either space group P4(1)2(1)2 or P4(3)2(1)2. The cell dimensions are a = b = 69.07 A and c = 113.26 A. The crystals contain one neurophysin-oxytocin dimer per asymmetric unit. Based on a Vm of 2.9 A3/Da, the solvent content is calculated to be 58%. Chromatographic analysis of the dissolved crystals suggests the presence of three oxytocin molecules per neurophysin dimer. 相似文献
2.
I Andersson A C Tj?der E Cedergren-Zeppezauer C I Br?ndén 《The Journal of biological chemistry》1983,258(23):14088-14090
Ribulose 1,5-bisphosphate carboxylase/oxygenase has been purified from spinach and crystallized by equilibrium vapor diffusion with polyethylene glycol 6000 as a precipitant. Crystals suitable for x-ray studies were obtained from a binary complex with a transition state analogue, 2-C-carboxy-D-arabinitol 1,5-bisphosphate, and a quaternary complex with 2-C-carboxy-D-arabinitol 1,5-bisphosphate, Mg2+, and HCO-3. Two forms of crystals were obtained in the presence of 2-C-carboxy-D-arabinitol 1,5-bisphosphate. Form B crystals are plates which have orthorhombic space group P2(1)2(1)2 with unit cell dimensions a = 184 A, b = 218 A, and c = 119 A. Form C crystals are tetragonal needles with space group I422 and with cell dimensions a = b = 275 A and c = 178 A. In both forms, the asymmetric unit contains half a molecule. 相似文献
3.
Preliminary X-ray crystallographic studies of pig kidney fructose-1,6-bisphosphatase 总被引:2,自引:0,他引:2
B A Seaton R L Campbell G A Petsko D R Rose I Edelstein F Marcus 《The Journal of biological chemistry》1984,259(14):8915-8916
Preliminary x-ray data have been obtained from large single crystals of pig kidney fructose-1,6-bisphosphatase, grown from polyethylene glycol. The crystals have the symmetry of space group P3(1)21 or its enantiomorph P3(2)21, contain two subunits of the 146,000-dalton tetramer/asymmetric unit, and diffract to 2.9-A resolution on still photographs. The unit cell dimensions are a = b = 132.5 A and c = 68.0 A. Small single crystals have been grown in the presence of the inhibitor fructose 2,6-bisphosphate, with and without the allosteric effector AMP added. Crystals grown in the presence of both ligands are isomorphous with native crystals and generate diffraction patterns that show significant intensity changes. 相似文献
4.
H M Holden T E Meyer M A Cusanovich I Rayment 《The Journal of biological chemistry》1986,261(31):14746-14747
Crystals of the high-potential iron-sulfur protein from Ectothiorhodospira halophila strain BN 9626 have been grown from 3.4 to 3.5 M ammonium sulfate solutions at pH 7.5. The crystals belong to the space group P21 with unit cell dimensions of a = 60.00 A, b = 31.94 A, c = 40.27 A, and beta = 100.5 degrees. There are 2 molecules/asymmetric unit. The crystals diffract to at least 1.8 A, are stable in the x-ray beam, and are suitable for a high resolution x-ray crystallographic analysis. 相似文献
5.
A Glasfeld G K Farber D Ringe T Marcel D Drocourt G Tiraby G A Petsko 《The Journal of biological chemistry》1988,263(29):14612-14613
Crystals of the tetrameric xylose isomerase from Streptomyces violaceoniger have been examined by x-ray analysis. Octahedral crystals with a maximum dimension of 0.7 mm were grown from ammonium sulfate solution. They possess the symmetry of P4(1)2(1)2 or P4(3)2(1)2 space groups, which are crystallographically indistinguishable. The unit cell dimensions are a = b = 140 A and c = 134 A. There is one tetramer of molecular weight 160,000 per asymmetric unit. The crystals diffract to 2.2 A. 相似文献
6.
Crystallization and preliminary X-ray investigation reveals that tumor necrosis factor is a compact trimer furnished with 3-fold symmetry 总被引:2,自引:0,他引:2
Crystals of recombinant human tumor necrosis factor produced by Escherichia coli have been obtained under different conditions. Crystals suitable for X-ray studies are produced by a vapor diffusion technique using sodium phosphate as both precipitant and buffer at pH 6.5. The crystals belong to the cubic space group, P2(1)3 with unit cell dimensions a = b = c = 95.7 A (1 A = 0.1 nm). Preliminary photography reveals that the crystals are moderately stable to X-rays and diffract to at least 3 A resolution. The diffraction data for native crystals have been collected on a diffractometer at 3 A resolution. Another crystal form, which appeared in a solution containing sodium phosphate at pH 8.0, has the trigonal space group P3 with unit cell dimensions a = b = 63.8 A and c = 54.4 A, and produces measurable reflections to a resolution of 3 A. Hexagonal crystals also have been obtained by the use of polyethylene glycol as precipitant in the range pH 7.6 to 8.0; however, the crystals are fragile and unstable to X-rays. Conservation of 3-fold symmetry in the different crystal forms obtained could reflect the ability of tumor necrosis factor molecules to form trimers in solution and probably the nature of binding of the molecules to cellular receptors. 相似文献
7.
Crystals of the calcium-containing lysozyme from horse milk have been grown by precipitation with sodium phosphate. The crystals are orthorhombic space group P2(1)2(1)2(1) with cell dimensions a = 53.2, b = 57.1, and c = 38.2 A and contain a single molecule in the asymmetric unit. The crystals are suitable for high resolution x-ray structural analysis. 相似文献
8.
Crystals of the aspartate aminotransferase from Escherichia coli (aspC gene product) have been examined by X-ray analysis. The crystals grow as elongated rectangular prisms, with the symmetry of space group C2221. Unit cell dimensions are a = 156 A, b = 87.6 A, c = 80.6 A and alpha = beta = gamma = 90 degrees. There is one protein subunit of molecular weight 43,600 per asymmetric unit. 相似文献
9.
F Dyda W Furey S Swaminathan M Sax B Farrenkopf F Jordan 《The Journal of biological chemistry》1990,265(29):17413-17415
Single crystals of the thiamin diphosphate (the vitamin B1 coenzyme)-dependent enzyme pyruvate decarboxylase (EC 4.1.1.1) from brewers' yeast have been grown using polyethylene glycol as a precipitating agent. Crystals of the homotetrameric version alpha 4 of the holoenzyme are triclinic, space group P1, with cell constants a = 81.0, b = 82.4, c = 116.6 A, alpha = 69.5 beta = 72.6, gamma = 62.4 degrees. The crystals are reasonably stable in a rotating anode x-ray beam and diffract to at least 2.5 A resolution. The Vm value of 2.55 A/dalton is consistent with a unit cell containing four subunits with mass of approximately 60 kDa each. Rotation function results with native data indicate strong non-crystallographic 222 symmetry relating the four identical subunits, thus density averaging methods are likely to play a role in the structure determination. 相似文献
10.
M J Eck B Beutler G Kuo J P Merryweather S R Sprang 《The Journal of biological chemistry》1988,263(26):12816-12819
Crystals of tumor necrosis factor (TNF) have been obtained in two forms. Rhombohedral crystals grow in 1.8 to 2.0 M ammonium sulfite, pH 7.8 at 21 degrees C, and tetragonal crystals grow in 2.6 M magnesium sulfate, pH 5.5 at 25 degrees C. Analysis of TNF by isoelectric focusing under native and denaturing conditions indicates that TNF molecules exist as trimers in solution. The rhombohedral cachectin crystals belong to space group R3 and have unit cell constants a = b = c = 47.65 A and alpha = beta = gamma = 88.1 degrees. Density determinations and the space group indicate that the unit cell contains one 51,000-dalton trimer. These crystals are stable in the x-ray beam and diffract to at least 1.85 A but are apparently twinned by merohedry. The tetragonal crystals are space group P4(3)2(1)2 or its enantiomorph P4(1)2(1)2 and have unit cell constants a = b = 95.08, c = 117.49. The asymmetric unit contains one trimer; the crystals are stable in the x-ray beam and diffract to beyond 3 A. 相似文献
11.
Preliminary crystallographic investigations of glycinamide ribonucleotide transformylase 总被引:1,自引:0,他引:1
E A Stura D L Johnson J Inglese J M Smith S J Benkovic I A Wilson 《The Journal of biological chemistry》1989,264(16):9703-9706
Crystals of glycinamide ribonucleotide transformylase have been grown from 0.4 to 1 M ammonium sulfate, 0.6 to 1 M sodium-potassium phosphate, or 0.65 to 1 M citrate in the pH range 4.5-7.0. The single crystals display variable morphology with varying pH. The crystals belong to the orthorhombic space group C222 with cell dimensions a = 141.4 A, b = 98.2 A, c = 103.5 A. Co-crystals have also been obtained in the presence of the inhibitor 5,8-dideazafolate (KI = 18 microM) under similar crystallization conditions. Crystals of a chemically modified enzyme, iodinated at Cys-21, were grown under similar conditions within the pH range 6.5-7.0. These crystals are isomorphous with the unmodified enzyme. Crystals suitable for high resolution (less than 2.5 A) x-ray diffraction studies have been obtained for each of the above. 相似文献
12.
A software package, XRayView, has been developed that uses interactive computer graphics to introduce basic concepts of x-ray diffraction by crystals, including the reciprocal lattice, the Ewald sphere construction, Laue cones, the wavelength dependence of the reciprocal lattice, primitive and centered lattices and systematic extinctions, rotation photography. Laue photography, space group determination and Laue group symmetry, and the alignment of crystals by examination of reciprocal space. XRayView is designed with "user-friendliness" in mind, using pull-down menus to control the program. Many of the experiences of using real x-ray diffraction equipment to examine crystalline diffraction can be simulated. Exercises are available on-line to guide the users through many typical x-ray diffraction experiments. 相似文献
13.
Well formed, tetragonal prisms of succinyl-CoA synthetase from Escherichia coli have been crystallized at room temperature from ammonium sulfate and mixtures of sodium and potassium phosphates. A systematic survey of the conditions for crystallization of the enzyme has been carried out. This has shown the addition of a small amount of an organic solvent (acetone, 2-methyl-2,4-pentanediol, tert-butyl alcohol, or tertamyl alcohol) to the phosphate media and of CoA to the sulfate media to be beneficial in producing large, single crystals suitable for analysis by x-ray diffraction methods. Preliminary examination of precession photographs reveals that the crystals from phosphate media have a unit cell of symmetry P4222 with dimensions a = b = 94 A and c = 248 A. Evidence suggests that there may be only half of the (alpha beta)2 tetramer/asymmetric unit in these crystals. The crystals from ammonium sulfate media have unit cell dimensions of a = b = 99 A and c = 399 A, a space group of P4122 (P4322), and one tetramer/asymmetric unit. They diffract to a resolution of 3.4 A. Both crystal types have large solvent contents of about 65% of the unit cell volumes. A parameter called "quality index" is introduced to facilitate comparison of crystals grown under a variety of conditions with respect to their quality of x-ray diffraction. 相似文献
14.
Preliminary crystallographic studies of the amino terminal half of human lactoferrin in its iron-saturated and iron-free forms. 总被引:1,自引:0,他引:1
C L Day G E Norris B F Anderson J W Tweedie E N Baker 《Journal of molecular biology》1992,228(3):973-974
The amino terminal half of human lactoferrin (LfN) produced from transfected baby hamster kidney cells has been crystallized in its iron-saturated and iron-free forms. The crystals of glycosylated LfN and deglycosylated LfN are monoclinic, space group C2, with cell dimensions a = 133.0 A, b = 58.3 A, c = 58.3 A, alpha = 90.0 degrees, beta = 114.7 degrees, gamma = 90.0 degrees, and one molecule per asymmetric unit. Crystals of apo LfN have also been prepared using deglycosylated protein. These crystals are tetragonal, space group P4(1)2(1)2 (or P4(3)2(1)2), with cell dimensions of a = b = 58.4 A and c = 217.2 A and one molecule per asymmetric unit. Both the iron-saturated and the iron-free crystals are suitable for high resolution X-ray analysis. 相似文献
15.
Crystals of apo- and holo-D-glyceraldehyde-3-phosphate dehydrogenase from the tail muscle of the Mediterranean lobster Palinurus vulgaris, previously found to be suitable for single crystal microspectrophotometric studies of catalytic activity in the crystalline state, have been examined by x-ray crystallography. The two forms are isomorphous, space group C 2 with cell dimensions a=128.4 A, b=99.9 A, c=80.3 A,beta=113.4 degrees. These data are consistent with a molecular weight of 73,000 in the crystallographic asymmetric unit, indicating that the tetrameric molecule possesses an exact 2-fold axis both in the presence and in the absence of NAD+. Analysis of the intensity distribution of conventional x-ray precession photographs shows that two further noncrystallographic diads are present and that the molecule has the 2 pseudo 22 symmetry found in other D-glyceraldehyde-3-phosphate dehydrogenases. Binding of NAD+ to apoenzyme in solution, at 25 degrees C, is anticooperative and it can be satisfactorily described by assuming two classes of coenzyme binding sites. 相似文献
16.
Crystals of lipoxygenase-1 from soybeans have been grown by the method of vapor diffusion in the presence of sodium formate, ammonium acetate, and lithium chloride at pH 7.0. This enzyme contains a non-heme iron and is closely related to a human lipoxygenase found in leukocytes that participates in the biosynthesis of leukotrienes and lipoxins. The crystals are monoclinic space group C2 with cell dimensions of a = 183.8 A, b = 123.2 A, c = 94.3 A and beta = 102.9 degrees. They diffract beyond 2.7 A, are stable for several days in the x-ray beam, and appear to be suitable for x-ray diffraction studies. 相似文献
17.
H M Holden M R Kanost J H Law I Rayment M A Wells 《The Journal of biological chemistry》1988,263(8):3960-3962
Crystals of apolipophorin III, isolated from the locust Locusta migratoria, have been reproducibly grown from ammonium sulfate solutions and are well suited for an x-ray crystallographic analysis. Locust apolipophorin III is a glycosylated protein with a molecular weight of 19,100 and interacts with lipophorin, the major lipoprotein complex in insects. The crystals belong to the space group P6122 or P6522 with unit cell dimensions of a = b = 67.5 A, c = 155.6 A and diffract to a nominal resolution of 2.5 A. They are physically robust and are stable in the x-ray beam for over a week. A complete native x-ray data set has been collected and processed to 3.0-A resolution. 相似文献
18.
R Celikel X P Dai G C Stewart S L Sutrina M H Saier N H Xuong J Reizer 《Journal of molecular biology》1991,222(4):857-859
The IIA constituent of the lactose permease from Staphylococcus aureus has been crystallized in two different forms. Crystals of form I have been grown from polyethylene glycol 4000 with beta-octyl glucoside. They diffract to 3.0 A resolution and belong to space group C2 with unit cell dimensions a = 141.7 A, b = 130.7 A, c = 96.5 A and beta = 96.2 degrees. Form II crystals have been obtained from a solution containing polyethylene glycol 400, ammonium sulfate and manganese chloride. They diffract to at least 2.8 A resolution and belong to space group P2(1)2(1)2(1) with unit cell dimensions a = 89.9 A, b = 101.5 A and c = 90.9 A. 相似文献
19.
Crystals of the colicin E3-immunity protein complex have been grown from solutions of citrate at pH 5.6. The crystals are monoclinic, space group P2(1), with unit cell dimensions a = 67.71, b = 196.67, c = 85.58 A, and beta = 113.67 degrees. The crystals diffract to 3-A resolution and are stable in the x-ray beam for at least a day. Although the stoichiometry of the complex in solution is 1:1 there are two, three, or four such binary complex molecules in the asymmetric unit. 相似文献
20.
J M Rondeau J P Samama B Samama P Barth D Moras J F Biellmann 《Journal of molecular biology》1987,195(4):945-948
Crystals of pig lens aldose reductase have been grown from polyethylene glycol solutions at pH 6.2 and analysed by X-ray diffraction. Two crystal forms were obtained. The first belongs to space group P1 with unit cell dimensions a = 81.3 A, b = 85.9 A, c = 56.6 A, alpha = 102.3 degrees, beta = 103.3 degrees, gamma = 79.0 degrees, with four molecules in the unit cell related by a 222 non-crystallographic symmetry. The second crystal form is hexagonal. The space group is P6(2)22 with a = b = 101 A, c = 257 A and two molecules in the asymmetric unit. Both forms are suitable for X-ray structure analysis to better than 3 A resolution. 相似文献