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1.
Crystals of human plasma retinol-binding protein have been obtained from 4.5 m-NaCl buffered at pH 6.8 with 20 mm-cacodylate. The crystals are trigonal with space group R3 and unit cell dimensions, referred to the hexagonal system. a = b = 104.2 A? and c = 74.5 A?. The crystals diffract to a resolution of 2.0 Å.  相似文献   

2.
A “naturally occurring” human κI VL dimer, designated Wat, has been isolated and crystallized. Protein Wat consists of two non-covalently bound monomers, each having a molecular weight of ~ 11,500. The monomer subunit is composed of an entire variable region light chain (VL) domain closely homologous to that of the κI Bence Jones protein Roy (Hilschmann &; Craig, 1965) as evidenced from amino acid composition, tryptic peptide map, and sequence analysis. Immunochemical studies substantiated that protein Wat is of the κ chain subgroup κI and lacks the isotypic and allotypic antigenic determinants associated with the κ constant region light chain domain. Two types of crystals of VL dimer Wat were obtained from ammonium sulfate or polyethylene glycol solutions. The type I crystals have unit cell dimensions of a = b = 82.6 A?, c = 60.3 A?, and the space group is hexagonal P62 or P64. The asymmetric unit consists of one VL dimer; the fractional volume of unit cell occupied by solvent is 0.51. The unit cell dimensions of the type II crystals are a = b = 1,08.3 A?, c = 108.8 A?; the space group is hexagonal P6122 or P6522. Three variable domains constitute the asymmetric unit of the type II crystals; the fractional value of the solvent (0.52) is compatible with the value obtained for the type I crystals.  相似文献   

3.
Belladonna mottle virus belongs to the turnip yellows mosaic virus group of the small spherical plant viruses. It contains 180 protein subunits, which are arranged in a T = 3 icosahedral surface lattice. The top and bottom viral components crystallize isomorphously in hexagonal space group R3 (a = b = 296 A?, c = 729 A?). The unit cell contains three virus particles, while the crystallographic asymmetric unit consists of only one-third of a particle. X-ray diffraction data from the crystals extend to at least 3.8 Å resolution.  相似文献   

4.
Tyrocidine A was crystallized from 2-methyl-2,4-pentanediol and water, or methanol, to yield crystals that are large enough for X-ray diffraction studies. Four crystals were examined; three were in equilibrium with mother liquor and the fourth was air-dried. They belong to the rhombohedral space group R32. Parameters of the hexagonal cell of the fully solvated crystals vary slightly and are approximately a = 34 A? and c = 50 A?. The asymmetric unit consists of one molecule of tyrocidine and several molecules of 2-methyl-2,4-pentanediol. Air-dried crystals appear to contain about half the number of solvent molecules. Three-dimensional X-ray diffraction data showing a maximum resolution of s = (1.7 A?)?1 have been recorded.  相似文献   

5.
Crystals have been obtained of a subunit of Limulus polyphemus hemocyanin. The blue crystals have the symmetry of the space group R32 with hexagonal lattice parameters a = 115 a?, c = 285 A?. There is one 70,000 molecular weight subunit per asymmetric unit. Each subunit contains two non-heme copper atoms and can reversibly bind one oxygen molecule.  相似文献   

6.
Purification and crystallisation procedures are reported for azurin and cytochrome c′ from Alcaligenes denitrificans and Alcaligenes sp. NCIB 11015. The azurin crystals from A. denitrificans are suitable for high-resolution X-ray structure analysis. They are orthorhombic, space group C2221 (with marked tetragonal pseudo-symmetry), cell dimensions a = 75.0 A?, b = 74.1 A?, c = 99.5 A?, with two molecules per asymmetric unit. The cytochrome c′ crystals from both species are hexagonal, space group P6122 (or P6522), cell dimensions a = b = 54.7 A?, c ~ 185 A?, γ = 120 °, with one subunit (molecular weight 14,000) in the asymmetric unit.  相似文献   

7.
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   

8.
Conditions have been established for the crystallization of tyrosyl-transfer RNA synthetase from Bacillus stearothermophilus at room temperature. The crystals are extremely well-ordered, exhibiting diffraction spots out to at least 2.7 Å, and can be grown to a convenient size for X-ray crystallographic analysis. The crystals are trigonal with a space group P3121, the unit cell having dimensions of a = 64.4 A? and c = 238 A?; the crystallographic asymmetric unit is probably one subunit of the dimeric (2 × 45,000, mol. wt) enzyme. The enzyme crystals are extremely stable and exhibit good resistance to radiation damage. This amino-acyl-tRNA synthetase appears to be amenable to complete structure determination by X-ray crystallography.  相似文献   

9.
Crystals of myohemerythrin   总被引:1,自引:0,他引:1  
Crystals have been grown of metazide myohemerythrin from the sipunculid Dendrostomum pyroides. The crystals are in space group P212121 and have unit cell dimensions of a = 41.6 A?, b = 80.0 A?and c = 37.8 A?. An asymmetric unit contains a single myohemerythrin molecule.  相似文献   

10.
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   

11.
Two crystal modifications of the monomeric haemoglobin from the flatworm Dicrocoelium dendriticum have been obtained by vapour diffusion against buffered polyethylene glycol solutions. Both the triclinic and hexagonal crystals contain cyanomethaemoglobin. The triclinic modification, space group PI, a = 37.1 A?, b = 39.9 A?, c = 49.0 A?, α = 88.8 °, β = 76.8 °, γ = 64.6 °, with two molecules, Mr = 16,750 each, per unit cell, has been selected for a detailed crystallographic study.  相似文献   

12.
Crystals of 5-enolpyruvylshikimate 3-phosphate synthase from Escherichia coli have been grown out of ammonium sulfate by the hanging drop method of vapor diffusion. The crystals belong to the hexagonal space group P6122 or P6522, with a = 124 A? and c = 381 A?, and diffract to 3.8 Å resolution.  相似文献   

13.
The gene 5 protein from bacteriophage fd, which binds to single-stranded progeny fd DNA, was obtained as large single crystals and subjected to X-ray diffraction analysis. The crystals are of monoclinic space group C2 with a = 75.8 A?, b = 28.0 A?, c = 42.5 A? and β = 103 °12′. The unit cell has one molecule of 9800 daltons as the asymmetric unit.  相似文献   

14.
Large crystals of human transferrin have been grown from polyethylene glycol solutions. The crystals are orthorhombic, space group P212121, with a = 78 A?, b = 94 A? and c = 112 A?. Density measurements indicate that there are four transferrin molecules in the unit cell.  相似文献   

15.
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   

16.
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   

17.
Crystals of the bacteriophage λ Cro repressor protein that are suitable for X-ray diffraction studies have been obtained. Preliminary crystallographic analysis reveals that the space group is R32, the cell dimensions in the hexagonal system are a = b = 91·9 A?, c = 268·9 A?, and there are three dimers per asymmetric unit.  相似文献   

18.
Crystals of crambin, a plant seed protein of molecular weight 5000, diffract X-rays strongly to the interplanar spacing limit of 0.88 Å. These diffraction data should allow a definition of atomic structure that is on a par with that typically obtained from crystals of small organic molecules. The crystals are in space group P21 and have unit cell dimensions a = 41.1 A?, b = 18.7 A?, c = 22·7 A?, and β = 90.6 °. The asymmetric unit contains one protein molecule.  相似文献   

19.
An orthorhombic form of beef liver catalase crystals has been examined by X-ray diffraction and electron microscopy. The space group is P212121 with a = 89A?, b = 140A?, and c = 231A?. Electron micrographs show the presence of broad channels arrayed in a hexagonal manner. The solvent content of these orthorhombic crystals is considerably less than that for previously reported trigonal crystals of beef liver catalase although the packing arrangement appears to be virtually the same, suggesting a possible symmetry transition upon dehydration.  相似文献   

20.
Single crystals of an l-arabinose-binding protein from Escherichia coli B/r suitable for a high-resolution structural analysis have been obtained. An X-ray examination of the orthorhombic crystals shows the space group is P212121, with unit cell dimensions: a = 55.3 A?, b = 71.4 A? and c = 77.5 A?. The asymmetric unit contains one protein molecule with a molecular weight of 38,000.  相似文献   

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