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1.
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   

2.
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   

3.
The lectin from the seeds of Abrus precatorius has been crystallized and the crystals subjected to study by X-ray diffraction and electron microscopy. Three closely related crystal forms were obtained, of orthorhombic space group P212121 with a = 138 A?, b = 142 A?, and c = 173 A?, of tetragonal space group P41212 with a = b = 136 A?, c = 176 A?, and a twinned intermediate of the first two. From electron microscopy and two-dimensional spatial filtering of electron micrographs of the crystals, the molecule appears to consist of four similar domains grouped in a roughly planar diamond-shaped arrangement having a local intramolecular dyad axis. The average diameter of the Abrus lectin molecule is 50 to 60 Å and the individual domains appear to have a diameter of about 25 Å.  相似文献   

4.
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   

5.
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   

6.
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   

7.
Collagenase from the larvae of the arthropod Hypoderma lineatum has been crystallized. The crystals are tetragonal, space group I422, a = b = 112 A?, c = 166 A?, with two molecules in the asymmetric unit.  相似文献   

8.
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   

9.
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   

10.
Auromomycin and macromomycin from the organism Streptomyces macromomyceticus have been crystallized. The X-ray diffraction pattern of crystals of each molecule is consistent with space group P21212 with cell parameters a = 46.45 A?, b = 54.34 A? and c = 42.03 A? for auromomycin, and a = 46.45 A?, b = 54.52 A? and c = 41.54 A? for macromomycin. Diffraction analysis of auromomycin is in progress.  相似文献   

11.
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   

12.
Large hexagonal crystals of ricinus lectin, present as a major component in the seeds of Ricinus communis, have been obtained at 4 °C in the presence of polyethylene glycol 6000 by vapor diffusion against media containing acetic acid. The crystals are of space group P622, with hexagonal unit cell parameters a = b = 166 A? and c = 341 A?. The asymmetric unit contains two molecules of molecular weight 125,000. The crystals are extremely unstable, both to environmental changes and to X-irradiation, and have a solvent content of approximately 55% by volume.  相似文献   

13.
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   

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 parvalbumin IIIf of the superfast swimbladder muscle of Opsanus tau has been crystallized by a vapor diffusion technique using (NH4)2SO4 as a precipitant agent. The crystals belong to space group P21, with a unit cell a = 27.31 A?, b = 58.75 A?, c = 30.83 A? and β = 98 ° 30′, and the asymmetric unit contains one molecule. These crystals are suitable for a high resolution crystallographic investigation.  相似文献   

16.
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   

17.
Reassembled alfalfa mosaic virus coat protein was partially digested with trypsin to remove the first 26 amino acids (Bol et al., 1974). These particles are empty icosahedral protein shells built with 60 alfalfa mosaic virus protein subunits. This aggregate has been crystallized in two different crystal forms, one of which diffracts X-rays to at least 3.4 Å resolution. The type I crystals (space group P63, a = 200 A?, c = 314 A?) contain two particles per cell separated by 195 Å with each sitting on a 3-fold axis. The type II crystals contain three particles per cell in space group P31or P32 (a = 201 A?, c = 485 A?). Other T = 1 viral particles have very similar diameters.  相似文献   

18.
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   

19.
The “goose-type” lysozyme isolated from the egg-white of the black swan Cygnus atratus has been crystallized. The space group is P21 with one molecule of protein in the asymmetric unit. The cell parameters are a = 46.2 A?, b = 65.1 A?, c = 38.7 A?, β = 110 °. The crystals diffract to a resolution of 2.25 Å and a set of diffraction data for the native protein has been collected photographically.  相似文献   

20.
The mitochondrial isoenzyme of aspartate aminotransferase (E.C. 2.6.1.1) has been isolated from chicken heart in an electrophoretically and immunologically homogeneous form. Large, well-diffracting single crystals of this enzyme, a dimeric molecule with a molecular weight of 90,000, have been grown by vapour phase diffusion against polyethylene glycol solutions. The crystals belong to space group P1. The unit cell, with the dimensions a = 55.6 A?, 6 = 58.7 A?, c = 76.0 A?, α = 85.3 °, β = 109.2 °, γ = 115.6 °, contains a single dimer. The diffraction pattern extends to at least 2.1 Å resolution.  相似文献   

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