X-ray Characterization (x-ray + characterization)

Distribution by Scientific Domains
Distribution within Chemistry

Kinds of X-ray Characterization

  • preliminary x-ray characterization


  • Selected Abstracts


    ChemInform Abstract: Synthesis and X-Ray Characterization of a New Polycondensed Heterocycle (II) Obtained by a Novel Mn(III)-Mediated Cascade Reaction of 2-Cyanophenyl Isothiocyanate.

    CHEMINFORM, Issue 50 2001
    Gianluca Calestani
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    A Combined Experimental and Theoretical Study of Anion,, Interactions in Bis(pyrşimidine) Salts

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 35 2007
    Angel Garcia-Raso
    Abstract We report the synthesis and X-ray characterization of an N,N, -tetramethylenebis(2-aminopyrimidinium) tetrafluoroborate salt that exhibits anion,, interactions that are responsible for the crystal packing. The anion forms a sandwich complex with two pyrimidine rings. When the anion is nitrate, the crystal packing is governed by anion,, interactions and hydrogen bonds, and the sandwich complex is not formed. Finally, a theoretical study of the anion,, interactions in charged pyrimidine rings is in good agreement with the experimental findings. (ę Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    X-ray characterization of epi-Ge/Pr2O3/Si(111) layer stacks by pole figures and reciprocal space mapping

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2009
    Peter Zaumseil
    Abstract An epi-Ge/Pr2O3/Si(111) layer structure prepared by consecutive steps of epitaxial deposition and annealing is used to demonstrate the possibility of a complex characterization by combination of different X-ray diffraction techniques. Especially pole figure measurements, reciprocal space mapping (RSM) and high resolution (HR) ,/2, scans at selected inclined netplanes were successfully used to determine the in-plane lattice orientation of the layers relative to the substrate, the strain state of all layers and the structural perfection of the epi-Ge film. It was found that the major part of the epi-Ge layer has the same type A stacking orientation as the Si substrate, but about 0.6% is of type B. The Pr2O3 buffer layer exhibits type B only. The strain state of oxide and epi-Ge was determined, and a small difference in the lattice constant of type A and B epi-Ge was found. Microtwins lying in inclined {111} planes were unambiguously identified by pole figure measurements as the dominating structural defects in the epi-Ge layer. They cause a characteristic scattering pattern in reciprocal space maps. The proposed combination of X-ray techniques allows a relatively fast, integral and non-destructive analysis of heteroepitaxial semiconductor oxide semiconductor structures. [source]


    X-ray characterization of periodic sub-nm surface relief gratings

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2007
    P. Zaumseil
    Abstract Line and cross lattices of 260 and 360 nm pitch were prepared by covering p-doped Si(100) substrates with photoresist, structuring and implanting with 3 Î 1015 cm,2, 45 keV As+ ions. These doping lattices with n+,p periodicity were investigated by X-ray diffraction (XRD) and reflectivity (XRR). While XRD did not show any signal of the periodic structure, XRR revealed a clear periodic diffraction pattern related to the pitch of the doping lattice. The features of this pattern as a function of the lattice orientation are discussed in detail for the cross lattice. Atomic force microscopy showed that the measured diffraction pattern is caused by a surface relief grating with sub-nm amplitude, which was generated by a final doping-dependent etching step during sample preparation. (ę 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Deposition of nano-crystalline lead chalcogenide thin films using a simple electrochemical technique

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2008
    Nillohit Mukherjee
    Abstract Nanocrystalline thin films of lead chalcogenides (PbS, PbSe and PbTe) were deposited on transparent conducting oxide (TCO) coated glass substrates at room temperature using a simple electrochemical (galvanic) technique, from suitable electrolytic solutions and without the application of any external bias. X-ray characterization revealed that PbS, PbSe and PbTe thin films were all of cubic phase. The formation of nanocrystallites with dense and compact surface morphology was detected from FESEM and AFM measurements. The nanocrystalline films showed ,blue shifted' IR absorption. Hall measurements showed the materials to be p-type in nature with carrier concentration in the range 1019 , 1020/cm3. (ę 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Crystallization and preliminary X-ray characterization of a novel calcium-binding protein AtCBL2 from Arabidopsis thaliana

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2003
    Masamichi Nagae
    A new family of calcineurin B-like calcium-binding proteins has recently been identified in Arabidopsis thaliana. AtCBL2, a member of this family, has been crystallized in the presence of calcium ions using polyethylene glycol as a precipitant at 293,K. The crystals belong to space group C2221, with unit-cell parameters a = 83.9, b = 118.1, c = 49.1,┼. The asymmetric unit contains one molecule, with a VM of 2.36,┼3,Da,1 and a solvent content of 48%. Native diffraction data to 2.1,┼ resolution have been collected using synchrotron radiation at SPring-8. [source]


    Isolation, purification and preliminary X-ray characterization of Cpn60-2 (65,kDa heat-shock protein) from Mycobacterium tuberculosis

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2002
    Noam Adir
    Cpn60-2 is a member of a unique family of putative molecular chaperones homologous to GroEL (Cpn60) but of unknown function and found only in Mycobacterium tuberculosis and closely related species. Cpn60-2 has mainly been studied for its strong immunogenity. Here, the purification, crystallization and preliminary crystallographic analysis of M. tuberculosis Cpn60-2 are reported. The crystals belong to space group P2, with unit-cell parameters a = 57, b = 115.5, c = 81.5,┼, , = 95.5░, and contain a dimer in the asymmetric unit. The crystals diffract to 4.0,┼ using a Cu rotating-anode X-ray generator. [source]


    Alliin lyase (alliinase) from garlic (Allium sativum): crystallization and preliminary X-ray characterization

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2002
    Linda J. W. Shimon
    The enzyme alliinase has been isolated from garlic bulbs and crystallized. The crystals belong to space group P21, with unit-cell parameters a = 70.191, b = 127.006, c = 108.085,┼, , = 93.384░. They diffract to 2.2,┼ at liquid-nitrogen temperature. Analysis of the Patterson self-rotation function suggests that the crystals contain two dimeric molecules per asymmetric unit. [source]


    Crystallization and preliminary X-ray characterization of a thermostable pectate lyase from Thermotoga maritima

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 4 2002
    Michael A. McDonough
    Pectate lyase is an enzyme involved in the degradation of the pectate portion of the primary plant cell wall. A recombinant pectate lyase from Thermotoga maritima where three of the four cysteine residues have been mutated (C132I, C156N, C194L) has been crystallized. Crystals of the same morphology and trigonal space group R3 with similar unit-cell parameters were obtained under two different conditions. The first, 0.3,M (NH4)H2PO4 pH 4.2, gave crystals with a maximum size of 0.4 Î 0.2 Î 0.2,mm in one week that diffracted to a resolution of 1.87,┼ and had unit-cell parameters a = b = 80.6, c = 148.8,┼. The second, 0.1,M sodium acetate, 6%(w/v) PEG 4000 pH 6.5, gave the same size crystals in two weeks that diffracted to a resolution of 2.1,┼ and had unit-cell parameters a = b = 80.0, c = 150.1,┼. [source]


    Crystallization and preliminary X-ray analysis of the archaeosine tRNA-guanine transglycosylase from Pyrococcus horikoshii

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2001
    Ryuichiro Ishitani
    The archaeosine tRNA-guanine transglycosylase from the hyperthermophilic archaeon Pyrococcus horikoshii was crystallized and preliminary X-ray characterization was performed. Single crystals were grown by the hanging-drop vapour-diffusion method, using sodium/potassium phosphate and sodium acetate as precipitants. The space group is P41212 or P43212, with unit-cell parameters a = b = 99.28,(14), c = 363.74,(56),┼. The cryocooled crystals diffracted X-rays beyond 2.2,┼ resolution using synchrotron şradiation from station BL44XU at SPring-8 (Harima). Selenoşmethionine-substituted protein crystals were prepared in order to solve the structure by the MAD phasing method. [source]


    Crystallization of the cytotoxic domain of a ribosome-inactivating colicin in complex with its immunity protein

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 12 2000
    Stephen Carr
    The complex between the ribonuclease domain of the ribosome-inactivating colicin E3 and its protein inhibitor, the cognate immunity Im3, has been crystallized and preliminary X-ray characterization has been performed. Single crystals of the 1:1 complex were grown from hanging-drop vapour-diffusion experiments using 2-propanol as a precipitant. The space group is P3121 or P3221, with unit-cell parameters a = b = 93.7, c = 76.2,┼. When cryocooled, these crystals diffract to a resolution of 2.4,┼. A search for suitable conventional heavy-atom derivatives was unsuccessful and so Im3 mutants containing engineered cysteine or methionine residues have been produced for mercury soaks and selenomethionine-labelling experiments, respectively. [source]


    Crystallization and preliminary X-ray characterization of a catalytic and ATP-binding domain of a putative PhoR histidine kinase from the ,-radioresistant bacterium Deinococcus radiodurans

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2010
    S. Caria
    The gene product of histidine kinase DR2244 (putative phoR) encoded by Deinococcus radiodurans has been suggested to be involved in the PhoR,PhoB two-component regulatory system. This two-component signalling system is activated upon phosphate starvation in several bacteria, including D. radiodurans. Single crystals were obtained from a recombinant preparation of the catalytic/ATP-binding (CA) domain of D. radiodurans PhoR (79,224) overexpressed in Escherichia coli. The crystals belonged to space group P212121, with unit-cell parameters a = 46.9, b = 81.8, c = 204.6,┼. The crystals contained six molecules in the asymmetric unit. Diffraction data were collected to 2.4,┼ resolution on beamline ID23-2 of the European Synchrotron Radiation Facility. [source]


    Crystallization and preliminary X-ray characterization of the Skp1,Fbg3 complex

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2010
    Taichi Kumanomidou
    F-box proteins are the substrate-recognition components of Skp1,Cullin1,F-box protein,Rbx1 (SCF) ubiquitin ligase complexes. Fbs1, an F-box protein, binds specifically to proteins modified with high-mannose oligosaccharides. Fbg3, another F-box protein, has 51% sequence identity to Fbs1. Although the residues that are necessary for binding to oligosaccharides are conserved between Fbs1 and Fbg3, Fbg3 does not bind glycoproteins. Skp1 and Fbg3 were co-expressed in Escherichia coli and their complex was purified to homogeneity and crystallized. Microseeding combined with the sandwiched hanging-drop technique improved the quality of the resulting crystals. The plate-shaped crystals belonged to space group P212121, with unit-cell parameters a = 34.1, b = 76.6, c = 193.9,┼ and one molecule per asymmetric unit. [source]


    Crystallization and preliminary X-ray characterization of a PaaX-like protein from Sulfolobus solfataricus P2

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 8 2009
    Yi Cao
    PaaX is a global regulator of the phenylacetyl-coenzyme A catabolon that adjusts the expression of different operons to that of the paa -encoded central pathway. In this study, the PaaX-like protein from the hyperthermophilic archaeon Sulfolobus solfataricus P2 was successfully crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. Diffraction data were obtained to a resolution of 3.0,┼ using synchrotron radiation at the Photon Factory. The crystal belonged to space group P321, with unit-cell parameters a = 86.4, b = 86.4, c = 105.5,┼. [source]


    Crystallization and preliminary X-ray characterization of a glycerol dehydrogenase from the human pathogen Salmonella enterica serovar Typhimurium

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2009
    A. T. Gonšalves
    Glycerol dehydrogenase (GldA) encoded by the STM4108 gene (gldA) has been related to the synthesis of HilA, a major transcriptional regulator that is responsible for the expression of invasion genes in the human pathogen Salmonella enterica serovar Typhimurium. Single colourless crystals were obtained from a recombinant preparation of GldA overexpressed in Escherichia coli. They belonged to space group P2221, with unit-cell parameters a = 127.0, b = 160.1, c = 665.2,┼. The crystals contained a very large number of molecules in the asymmetric unit, probably 30,35. Diffraction data were collected to 3.5,┼ resolution using synchrotron radiation at the European Synchrotron Radiation Facility. [source]


    Heterologous expression, crystallization and preliminary X-ray characterization of CcCel6C, a glycoside hydrolase family 6 enzyme from the basidiomycete Coprinopsis cinerea

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2009
    Yuma Kurakata
    CcCel6C is a gene that encodes a glycoside hydrolase family 6 (GH6) enzyme in the Coprinopsis cinerea genome. In the evolutionary tree of GH6 enzymes, the encoded enzyme was closely related to Cel6B from Humicola insolens, previously called endoglucanase VI, while its amino-acid sequence revealed a region corresponding to the C-terminal active-site-enclosing loop typical of cellobiohydrolase II. Here, the crystallization of CcCel6C produced in Escherichia coli is reported. The square prismatic crystal belonged to the triclinic space group P1, with unit-cell parameters a = 44.04, b = 45.11, c = 48.90,┼, , = 77.81, , = 87.34, , = 68.79░. Diffraction data were collected to 1.6,┼ resolution. [source]


    Expression, purification and preliminary X-ray characterization of dl -2-haloacid dehalogenase from Methylobacterium sp.

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2007

    dl -2-Haloacid dehalogenase from Methylobacterium sp. CPA1 (dl -DEX Mb) is a unique enzyme that catalyzes the dehalogenation reaction without the formation of an ester intermediate. A recombinant form of dl -DEX Mb has been expressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. The crystal belongs to the hexagonal space group P63, with unit-cell parameters a = b = 186.2, c = 114.4,┼. The crystals are likely to contain between four and eight monomers in the asymmetric unit, with a VM value of 4.20,2.10,┼3,Da,1. A self-rotation function revealed peaks on the , = 180░ section. X-ray data have been collected to 1.75,┼ resolution. [source]


    Crystallization and preliminary X-ray characterization of 1,3-propanediol dehydrogenase from the human pathogen Klebsiella pneumoniae

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2007
    D. Maršal
    1,3-Propanediol dehydrogenase (1,3-PD-DH), encoded by the dhaT gene, is a key enzyme in the dissimilation process for converting glycerol to 1,3-propanediol in the human pathogen Klebsiella pneumoniae. Single colourless crystals were obtained from a recombinant preparation of 1,3-propanediol dehydrogenase overexpressed in Escherichia coli. The crystals belong to space group P21, with unit-cell parameters a = 91.9, b = 226.6, c = 232.6,┼, , = 92.9░. The crystals probably contain two decamers in the asymmetric unit, with a VM value of 3.07,┼3,Da,1 and an estimated solvent content of 59%. Diffraction data were collected to 2.7,┼ resolution using synchrotron radiation at the ID14-4 beamline of the European Synchrotron Radiation Facility. [source]


    Crystallization and preliminary X-ray characterization of aminopeptidase N from Escherichia coli

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2006
    Yuko Onohara
    A recombinant form of aminopeptidase N (molecular weight 99,kDa) from Escherichia coli was crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitating agent. The crystals belong to the hexagonal space group P3121, with unit-cell parameters a = b = 120.5, c = 171.0,┼. The crystals are most likely to contain one molecule in the asymmetric unit, with a VM value of 3.62,┼3,Da,1. Diffraction data were collected to 2.0,┼ resolution using Cu,K, radiation from a rotating-anode X-ray generator. [source]