The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Piotr Zieliński - One of the best experts on this subject based on the ideXlab platform.
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Anomalous X-ray diffraction with soft X-ray synchrotron radiation.
Cellular and Molecular Biology, 2000Co-Authors: Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Heinrich Stuhrmann, Piotr ZielińskiAbstract:Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like Uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing Uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of Uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect the performance of the beamline ID1 of ESRF at wavelengths beyond 3 A at the end of 1998. A gain by a factor 100 for diffraction experiments with 4.4 A photons was achieved in Autumn 1999 when two focusing mirrors had been added to the X-ray optics. Further progress is expected from area detectors more sensitive to soft X-rays. Both CCD detectors and image plates would provide a gain of two orders of measured intensity. Image plates would have the additional advantage that they can be bent cylindrically and thus cover a larger solid angle in reciprocal space. In many cases, samples need to be cooled: closed and open systems are presented. A comparison with the state of art of soft X-ray diffraction, as it had been reached at HASYLAB (Hamburg, Germany), and as it is developing at the Brookhaven National Laboratory (USA), is given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography
Journal of Synchrotron Radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, Carmen Berthet‐colominas, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its MV absorption edge (λMV = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the MV edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (λK = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24° were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography.
Journal of synchrotron radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its M(V) absorption edge (lambda(M(V)) = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the M(V) edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (lambda(K) = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24 degrees were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
Philippe Carpentier - One of the best experts on this subject based on the ideXlab platform.
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Anomalous X-ray diffraction with soft X-ray synchrotron radiation.
Cellular and Molecular Biology, 2000Co-Authors: Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Heinrich Stuhrmann, Piotr ZielińskiAbstract:Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like Uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing Uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of Uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect the performance of the beamline ID1 of ESRF at wavelengths beyond 3 A at the end of 1998. A gain by a factor 100 for diffraction experiments with 4.4 A photons was achieved in Autumn 1999 when two focusing mirrors had been added to the X-ray optics. Further progress is expected from area detectors more sensitive to soft X-rays. Both CCD detectors and image plates would provide a gain of two orders of measured intensity. Image plates would have the additional advantage that they can be bent cylindrically and thus cover a larger solid angle in reciprocal space. In many cases, samples need to be cooled: closed and open systems are presented. A comparison with the state of art of soft X-ray diffraction, as it had been reached at HASYLAB (Hamburg, Germany), and as it is developing at the Brookhaven National Laboratory (USA), is given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography
Journal of Synchrotron Radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, Carmen Berthet‐colominas, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its MV absorption edge (λMV = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the MV edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (λK = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24° were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography.
Journal of synchrotron radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its M(V) absorption edge (lambda(M(V)) = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the M(V) edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (lambda(K) = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24 degrees were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
Richard Kahn - One of the best experts on this subject based on the ideXlab platform.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography
Journal of Synchrotron Radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, Carmen Berthet‐colominas, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its MV absorption edge (λMV = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the MV edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (λK = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24° were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography.
Journal of synchrotron radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its M(V) absorption edge (lambda(M(V)) = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the M(V) edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (lambda(K) = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24 degrees were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
Stéphane Lequien - One of the best experts on this subject based on the ideXlab platform.
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Anomalous X-ray diffraction with soft X-ray synchrotron radiation.
Cellular and Molecular Biology, 2000Co-Authors: Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Heinrich Stuhrmann, Piotr ZielińskiAbstract:Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like Uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing Uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of Uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect the performance of the beamline ID1 of ESRF at wavelengths beyond 3 A at the end of 1998. A gain by a factor 100 for diffraction experiments with 4.4 A photons was achieved in Autumn 1999 when two focusing mirrors had been added to the X-ray optics. Further progress is expected from area detectors more sensitive to soft X-rays. Both CCD detectors and image plates would provide a gain of two orders of measured intensity. Image plates would have the additional advantage that they can be bent cylindrically and thus cover a larger solid angle in reciprocal space. In many cases, samples need to be cooled: closed and open systems are presented. A comparison with the state of art of soft X-ray diffraction, as it had been reached at HASYLAB (Hamburg, Germany), and as it is developing at the Brookhaven National Laboratory (USA), is given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography
Journal of Synchrotron Radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, Carmen Berthet‐colominas, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its MV absorption edge (λMV = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the MV edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (λK = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24° were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography.
Journal of synchrotron radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its M(V) absorption edge (lambda(M(V)) = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the M(V) edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (lambda(K) = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24 degrees were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
M.-l. Chesne - One of the best experts on this subject based on the ideXlab platform.
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Anomalous X-ray diffraction with soft X-ray synchrotron radiation.
Cellular and Molecular Biology, 2000Co-Authors: Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Heinrich Stuhrmann, Piotr ZielińskiAbstract:Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like Uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing Uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of Uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect the performance of the beamline ID1 of ESRF at wavelengths beyond 3 A at the end of 1998. A gain by a factor 100 for diffraction experiments with 4.4 A photons was achieved in Autumn 1999 when two focusing mirrors had been added to the X-ray optics. Further progress is expected from area detectors more sensitive to soft X-rays. Both CCD detectors and image plates would provide a gain of two orders of measured intensity. Image plates would have the additional advantage that they can be bent cylindrically and thus cover a larger solid angle in reciprocal space. In many cases, samples need to be cooled: closed and open systems are presented. A comparison with the state of art of soft X-ray diffraction, as it had been reached at HASYLAB (Hamburg, Germany), and as it is developing at the Brookhaven National Laboratory (USA), is given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography
Journal of Synchrotron Radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, Carmen Berthet‐colominas, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its MV absorption edge (λMV = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the MV edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (λK = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24° were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
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Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography.
Journal of synchrotron radiation, 2000Co-Authors: Richard Kahn, Philippe Carpentier, M. J. Capitán, M.-l. Chesne, Eric Fanchon, Stéphane Lequien, Dominique Thiaudière, J. Vicat, C Berthet-colominas, Piotr ZielińskiAbstract:The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of Uranium which exhibits an unusually strong anomalous dispersion at its M(V) absorption edge (lambda(M(V)) = 3.5 A). The anomalous scattering amplitude of Uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of Uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a Uranium Derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the M(V) edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (lambda(K) = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24 degrees were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.
