André Authier
- Published in print:
- 2013
- Published Online:
- September 2013
- ISBN:
- 9780199659845
- eISBN:
- 9780191748219
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199659845.003.0008
- Subject:
- Physics, Crystallography: Physics
This chapter recalls the early developments of X-ray crystallography and how it spread throughout the world, and the first theoretical and experimental investigations that led to the determination of ...
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This chapter recalls the early developments of X-ray crystallography and how it spread throughout the world, and the first theoretical and experimental investigations that led to the determination of crystal structures, from the simpler trial-and-error methods to the systematic use of space groups and the introduction of Fourier syntheses. The Lorentz and polarization factors and the atomic scattering factor were analysed. W. H. Bragg introduced the concept of integrated intensities, and W. L. Bragg that of absolute intensities. Expressions for the diffracted intensity by small and large perfect crystals were obtained by C. G. Darwin, who also introduced the notion of mosaic crystal to account for the observed diffracted intensities. It is shown how W. L. Bragg determined the structure of the trigonal carbonates from the simple observation of diffracted intensities by various reflecting planes. The discovery of powder diffraction by Debye and Sherrer in Germany and by Hull in the United States is recounted. The first applications of the rotating crystal method to crystal structure determinations are described. Finally, the determination of three landmark crystal structures is explained: hexamethylene tetramine, graphite, and the benzene ring.Less
This chapter recalls the early developments of X-ray crystallography and how it spread throughout the world, and the first theoretical and experimental investigations that led to the determination of crystal structures, from the simpler trial-and-error methods to the systematic use of space groups and the introduction of Fourier syntheses. The Lorentz and polarization factors and the atomic scattering factor were analysed. W. H. Bragg introduced the concept of integrated intensities, and W. L. Bragg that of absolute intensities. Expressions for the diffracted intensity by small and large perfect crystals were obtained by C. G. Darwin, who also introduced the notion of mosaic crystal to account for the observed diffracted intensities. It is shown how W. L. Bragg determined the structure of the trigonal carbonates from the simple observation of diffracted intensities by various reflecting planes. The discovery of powder diffraction by Debye and Sherrer in Germany and by Hull in the United States is recounted. The first applications of the rotating crystal method to crystal structure determinations are described. Finally, the determination of three landmark crystal structures is explained: hexamethylene tetramine, graphite, and the benzene ring.
Jane Skelly, Maninder K. Sohi, and Thil Batuwangala
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198520979
- eISBN:
- 9780191706295
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198520979.003.0001
- Subject:
- Biology, Biochemistry / Molecular Biology
The ideal protein-expression strategy for X-ray structural analysis should provide correctly folded, soluble, and active protein in sufficient quantities for successful crystallization. Subsequent ...
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The ideal protein-expression strategy for X-ray structural analysis should provide correctly folded, soluble, and active protein in sufficient quantities for successful crystallization. Subsequent isolation and purification must be designed to achieve a polished product as rapidly as possible, involving a minimum number of steps. The simplest and least expensive methods employ bacterial hosts such as Escherichia coli, Bacillus, and Staphylococcus but if the target protein is from an eukaryotic source requiring post-translational processing for full functionality, an eukaryotic vector-host system would be appropriate. This chapter discusses the processes of cloning and expression, and protein extraction and isolation.Less
The ideal protein-expression strategy for X-ray structural analysis should provide correctly folded, soluble, and active protein in sufficient quantities for successful crystallization. Subsequent isolation and purification must be designed to achieve a polished product as rapidly as possible, involving a minimum number of steps. The simplest and least expensive methods employ bacterial hosts such as Escherichia coli, Bacillus, and Staphylococcus but if the target protein is from an eukaryotic source requiring post-translational processing for full functionality, an eukaryotic vector-host system would be appropriate. This chapter discusses the processes of cloning and expression, and protein extraction and isolation.
André Authier
- Published in print:
- 2013
- Published Online:
- September 2013
- ISBN:
- 9780199659845
- eISBN:
- 9780191748219
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199659845.001.0001
- Subject:
- Physics, Crystallography: Physics
2012 marked the centenary of one of the most significant discoveries of the early twentieth century: the discovery of X-ray diffraction in March 1912 by Laue, Friedrich, and Knipping, and of the ...
More
2012 marked the centenary of one of the most significant discoveries of the early twentieth century: the discovery of X-ray diffraction in March 1912 by Laue, Friedrich, and Knipping, and of the birth of X-analysis with Bragg’s law in November 1912. The discovery of X-ray diffraction confirmed the wave nature of X-rays and the space-lattice hypothesis. The book stresses the unique role played by X-ray diffraction in the analysis of the structure of atoms and in the determination of the atomic structure of materials. It relates the discovery itself and the context in which it was made: the local context (Munich) and the scientific context (the discussions taking place at that time about the nature, wave or corpuscular, of X-rays, and about the concept of space lattice). The way the discovery spread round the world and the early investigations are described. The book explains how the basic theories of X-ray diffraction and the main methods of investigations were developed, and how the first crystal structures were determined, and recounts which were the first applications of X-ray crystallography in chemistry, mineralogy, material science, biology, physics, and X-ray spectroscopy. It also tells how the concept of space lattice matured between Ancient times and the end of the nineteenth century, and how our understanding of the nature of light has changed over time. The contributions of the main actors of the story, prior to the discovery, at the time of the discovery, and immediately afterwards, are described through their writings and are put into a contemporary context, accompanied by brief biographical details.Less
2012 marked the centenary of one of the most significant discoveries of the early twentieth century: the discovery of X-ray diffraction in March 1912 by Laue, Friedrich, and Knipping, and of the birth of X-analysis with Bragg’s law in November 1912. The discovery of X-ray diffraction confirmed the wave nature of X-rays and the space-lattice hypothesis. The book stresses the unique role played by X-ray diffraction in the analysis of the structure of atoms and in the determination of the atomic structure of materials. It relates the discovery itself and the context in which it was made: the local context (Munich) and the scientific context (the discussions taking place at that time about the nature, wave or corpuscular, of X-rays, and about the concept of space lattice). The way the discovery spread round the world and the early investigations are described. The book explains how the basic theories of X-ray diffraction and the main methods of investigations were developed, and how the first crystal structures were determined, and recounts which were the first applications of X-ray crystallography in chemistry, mineralogy, material science, biology, physics, and X-ray spectroscopy. It also tells how the concept of space lattice matured between Ancient times and the end of the nineteenth century, and how our understanding of the nature of light has changed over time. The contributions of the main actors of the story, prior to the discovery, at the time of the discovery, and immediately afterwards, are described through their writings and are put into a contemporary context, accompanied by brief biographical details.
André Authier
- Published in print:
- 2013
- Published Online:
- September 2013
- ISBN:
- 9780199659845
- eISBN:
- 9780191748219
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199659845.003.0001
- Subject:
- Physics, Crystallography: Physics
This chapter stresses the significance of the discovery of X-ray diffraction by Laue, Friedrich, and Knipping, at the time of the discovery and afterwards. The discovery confirmed the wave nature of ...
More
This chapter stresses the significance of the discovery of X-ray diffraction by Laue, Friedrich, and Knipping, at the time of the discovery and afterwards. The discovery confirmed the wave nature of X-rays, and the reaction of the supporters of the corpuscular theory, such as W. H. Bragg, is evoked. Laue’s discovery also confirmed the concept of space lattice, and the knowledge crystallographers had of that concept at that time is discussed. The discovery played a major role in the studies of the atomic structure of materials and of the structure of atoms. Its impact on X-ray spectroscopy and on the chemical, biochemical, physical, material, and mineralogical sciences is sketched in the last part of the chapter.Less
This chapter stresses the significance of the discovery of X-ray diffraction by Laue, Friedrich, and Knipping, at the time of the discovery and afterwards. The discovery confirmed the wave nature of X-rays, and the reaction of the supporters of the corpuscular theory, such as W. H. Bragg, is evoked. Laue’s discovery also confirmed the concept of space lattice, and the knowledge crystallographers had of that concept at that time is discussed. The discovery played a major role in the studies of the atomic structure of materials and of the structure of atoms. Its impact on X-ray spectroscopy and on the chemical, biochemical, physical, material, and mineralogical sciences is sketched in the last part of the chapter.
