首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 478 毫秒
1.
Two crystal forms of lysozyme from the egg white of the embden goose (Anser anser) have been obtained, both of which are suitable for X-ray diffraction analysis. The monoclinic form has space group P21 with cell dimensions a = 38.3 A?, b = 65.7 A?, c = 45.2 a?, β = 116 ° and the triclinic form (space group P1) has cell dimensions of a = 39.9 A?, b = 42.2 A?, c = 57.9 A? and α = 98.8 °, β = 102.5 °, γ = 90.5 °.  相似文献   

2.
Erysimum latent virus, a tymovirus, contains 180 protein subunits arranged in a T = 3 icosahedral surface lattice. A cubic crystal form (with space group P213 and a = 414 A?) and a monoclinic form (space group B2, a = 442 A?, b = 422 A?, c = 387 A?, γ = 95 °) have been observed. The asymmetric units of the two crystal forms contain one-third and one whole virus particle, respectively. Two possible packing arrangements of the virus particles in the monoclinic unit cell have been deduced from the low-angle diffraction patterns. X-ray diffraction data from the monoclinic crystals extend to at least 3·7 Å resolution.  相似文献   

3.
Three crystal forms of rabbit muscle creatine kinase have been grown, one of which seems suited to a high resolution X-ray diffraction study. The first form is of monoclinic space group P21 with a = 54 A?, b = 114 A?, c = 145 A?, β = 91 ° and has as the asymmetric unit two molecules of total molecular weight 160, 000. The second form, grown in the presence of mercurials, is of space group A2 with a = 52 A?, b = 165 A?, c = 237 A?, β = 91 ° and also has two molecules in the asymmetric unit. The third crystal form, grown in the presence of a high concentration of cysteine, is of apparent space group P212121, but evidence indicates that the true space group may be P21221. The dimensions of the orthorhombic unit cell are a = 47 A?, b = 86 A?, c = 125 A?, and the asymmetric unit contains a single protein subunit. Assuming the latter space group, then the creatine kinase molecule possesses a twofold axis relating two identical subunits.  相似文献   

4.
Exotoxin A from Pseudomonas aeruginosa has been crystallized in a form suitable for high resolution diffraction analysis. The crystals, grown in the presence of high concentrations of polyethylene glycol (20%, w/v) and of NaCl (1.5 m), are monoclinic and contain one monomeric toxin molecule per asymmetric unit. The space group is P21, with a = 60.6 A?, b = 100.2 A?, c = 59.8 A?, β = 98.6 °.  相似文献   

5.
Crystals of plastocyanins from pea and corn leaves have been obtained. Both are suitable for X-ray structure analysis with a resolution up to 1.8 Å. The crystal form of plastocyanin from pea leaves belongs to the space group P212121 with unit cell dimensions: a = 49.0 A?, b = 53.3 A?, c = 82.6 A?. The assumed number of protein molecules per asymmetric unit of the unit cell is two. Crystals of the oxidized (Cu2+) and reduced (Cu+) forms are isomorphic. No essential differences in spot intensities for the main zone with a resolution of 3 Å were revealed. The crystal form of plastocyanin from corn leaves belongs to the space group P1 with unit cell parameters: a = 24.8 A?, b = 30.0 A?, c = 58.5 A? and α = 96° 10′, β = 87°08′, γ = 78°40′. The assumed number of protein molecules per asymmetric unit is two.  相似文献   

6.
Macromomycin (Mr 12,000) is the apoprotein of the antitumor drug auromomycin, which inhibits DNA synthesis by causing single-strand breaks in DNA. Two orthorhombic crystal forms of macromomycin have been observed. The platelike crystals of one form belong to space group P212121, with cell dimensions a = 48·92 A?, b = 54·71 A?, c = 103·31 A?, Z = 8. The crystals of the second form are needle-shaped, and belong to space group P21212, with cell dimensions a = 46·1 A?, b = 54·4 A?, c = 41·2 A?, Z = 4. At this point in time, the platelike crystals appear the most suitable for continued crystallographic studies.  相似文献   

7.
The crystals of ribonuclease St, the extracellular ribonuclease from Streptomyces erythreus, have been obtained from (NH4)2SO4 solution with acetate buffer (pH 4.1). The crystals belong to a monoclinic space group C2 with dimensions a = 88.4 A?, b = 33.0 A?, c = 69.0 A?, β = 98.4 °. There are two protein molecules per asymmetric unit. The crystals diffract beyond 2.0 Å resolution.  相似文献   

8.
Superoxide dismutase from Bacillus stearothermophilus is a dimeric manganese-containing enzyme with a molecular weight of 40,000. It has been crystallised in the monoclinic space group P21 with unit cell dimensions of a = 50 A?, b = 70 A?, c = 69 A? and β = 111 ° 10′. The asymmetric unit appears to be the dimer.  相似文献   

9.
A monoclinic crystal form (P21, a = 140.4 A?, b = 85.0 A?, c = 94.5 A?, β= 130.1 °) of Δ5-3-ketosteroid isomerase from Pseudomonas testosteroni (EC 5.3.3.1), grown at pH 7.0, has been characterized. Crystal-density measurements show that the asymmetric unit contains 12 protomers (Mr = 13,394).  相似文献   

10.
The Mn superoxide dismutase from Escherichia coli has been obtained in three crystal forms: (I) from 68% saturated (NH4)2SO4, space group P222 or P2221, a = 47 A?, b = 103 A?, c = 47.5 A?, with one subunit per asymmetric unit; (II) from 50% polyethylene glycol 6000, space group C2221 (with approx. P41212 symmetry), a = 101 A?, b = 108 A?, c = 180 A?, with four subunits (2 molecules) per asymmetric unit; (III) from 52% polyethylene glycol with a different method of preparing the enzyme solution, space group P21212, a = 47 A?, b = 51 A?, c = 188 A?, with two subunits per asymmetric unit.The yeast mitochondrial Mn superoxide dismutase has yielded the same crystal form both from 30% 2-methyl-2,4-pentane diol and from 23% polyethylene glycol 6000: space group P212121, a = 63 A?, b = 115 A?, c = 125 A?, with four subunits (one molecule) per asymmetric unit.A full X-ray crystallographic study of at least one of these enzymes is planned.  相似文献   

11.
Crystals of calotropin DI (Mr 23,400), have been prepared by microdialysis against 5% (w/v) polyethylene glycol 20,000 in water, pH 7.0. They have orthorhombic space group P212121 with cell parameters a = 57.5 A?, b = 86.2 A?, c = 40.3 A?. Crystals of calotropin DII (Mr 24,000), prepared by the same technique against 5% (w/v) polyethylene glycol 20,000 in phosphate buffer of low ionic strength, pH 7.0, display monoclinic space group C2 with cell parameters a = 135.8 A?, b = 32.0 A?, c = 47.7 A?, β = 103.80 °. In both cases, there is only one molecule in the asymmetric unit.  相似文献   

12.
Crystals of mitogenic lectin from pea seeds (Pisum sativum) have been grown. The crystals are in space group P212121 with unit cell dimensions: a = 51.0 ± 0.2 A?, b = 617 ± 0.2 A?, c = 137.6 ± 0.5 A?. The asymmetric unit has one protein molecule.  相似文献   

13.
Wheat germ agglutinin crystallizes in two monoclinic space groups, P21 and C2, under identical crystallization conditions. Unit cell dimensions are a = 73.8 A?, b = 51.2 A?, c = 90.8 A?, γ = 90 ° for P21; a = 51.31 A?, b = 73.35 A?, c = 91.45 A?, β = 97.75 ° for C2, both with eight subunit molecules in the unit cell. The C2 crystals were chosen as suitable for investigating the three-dimensional structure to high resolution, because of their smaller asymmetric unit (containing the dimer), and also because they display better diffraction patterns.  相似文献   

14.
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   

15.
Three new crystal forms of cow α-lactalbumin are described. A trigonal form in space group P3121 or P3221 has unit cell dimensions: a = b = 57.4 A?, c = 75.0 A?. A hexagonal form in space group P622 has unit cell dimensions: a = b = 94.0 A?, c = 67.1 A?. A second trigonal form grown in the presence of calcium ions belongs to space group P321 with unit cell dimensions: a = b = 93.7 A?, c = 66.9 A?. The significance of these new crystal forms to the structure determination of cow α-laetalbumin is discussed.  相似文献   

16.
Soybean agglutinin crystallizes in the monoclinic space group C2 with unit cell dimensions a = 118.6 A?, b = 88.9 A?, c = 165.9 A?, β = 103.0 ° and one tetramer of 120,000 Mr per asymmetric unit. The crystals are suitable for high-resolution work.  相似文献   

17.
The esteroproteolytic enzyme, a serine protease from porcine pancreas, has been crystallized and characterized by X-ray diffraction. Two closely related crystal forms were observed. The unit cell dimensions of the first form are a = 59.2 A?, b = 96.4 A? and c = 47.4 A?, space group P21212 with one molecule (mol. wt 30,000) per asymmetric unit. The unit cell dimensions of the second form are a = 59.2 A?, b = 96.4 A? and c = 94.8 A?, space group P212121. Mercury derivatives of enzyme inhibitors were used to obtain multiple isomorphous heavy-atom substituents suitable for phase determination.  相似文献   

18.
Arc, a represser from Salmonella phage P22 has been crystallized from ammonium phosphate at pH 8.0. The crystals form in space group P212121 with a = 90.26 A?, b = 52.88 A? and c = 47.58 A?. The crystals diffract to 2.2 Å resolution.  相似文献   

19.
Pseudomonas aeruginosa cytochrome oxidase (nitrite reductase, cytochrome cd) has been crystallized in space group P21212 with cell dimensions a = 122.8 A?, b = 87.2 A?, c = 73.4 A?. Density measurements suggest that the asymmetric unit contains one 63,000 molecular weight subunit of the dimeric molecule. Crystal data agree well with electron microscopy of single molecules. The X-ray pattern extends beyond 2.5 Å resolution, and structure analysis is in progress.  相似文献   

20.
Renin isolated from the mouse submaxillary gland has been crystallized and is being subjected to X-ray diffraction analysis.The observed crystalline form has the following unit cell dimensions: a = 96.4 (1) A?, b = 104.4 (1) A?, c = 77.4 (1) A?, β = 101.2 (1) °, space group P21, Z = 8 (4 protein molecules in the asymmetric unit).Native data have been recorded at 5 Å resolution with an automatic diffractometer.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号