scholarly journals Optical control, selection and analysis of population dynamics in ultrafast protein X-ray crystallography

Author(s):  
Christopher D. M. Hutchison ◽  
Jasper J. van Thor

Ultrafast pump-probe X-ray crystallography has now been established at X-ray free electron lasers that operate at hard X-ray energies. We discuss the performance and development of current applications in terms of the available data quality and sensitivity to detect and analyse structural dynamics. A discussion of technical capabilities expected at future high repetition rate applications as well as future non-collinear multi-pulse schemes focuses on the possibility to advance the technique to the practical application of the X-ray crystallographic equivalent of an impulse time-domain Raman measurement of vibrational coherence. Furthermore, we present calculations of the magnitude of population differences and distributions prepared with ultrafast optical pumping of single crystals in the typical serial femtosecond crystallography geometry, which are developed for the general uniaxial and biaxial cases. The results present opportunities for polarization resolved anisotropic X-ray diffraction analysis of photochemical populations for the ultrafast time domain. This article is part of the theme issue ‘Measurement of ultrafast electronic and structural dynamics with X-rays’.

1979 ◽  
Vol 25 ◽  
pp. 74-143 ◽  

Walking along the Backs in Cambridge one day in the autumn of 1912 William Lawrence Bragg had an idea that led immediately to a dramatic advance in physics and has since transformed chemistry, mineralogy, metallurgy and, most recently, biology. He realized that the observations of X-ray diffraction by a crystal, which had been reported by von Laue and his associates earlier in that year, can be interpreted very simply as arising from reflexion of the X-rays by planes of atoms in the crystal and hence that the X-ray observations provide evidence from which the arrangement of atoms in the crystal may be determined. A few weeks of intensive work on simple inorganic compounds were enough to demonstrate the correctness of these ideas but the development of the method, at first in association with his father and later as the leader or guiding influence of a host of workers, was the labour of a lifetime. When he died on 1 July 1971, X-ray crystallography had revealed the arrangement of atoms in matter of all kinds from the simplest of salts to the macromolecules of the living cell. The story of his life is very largely the story of that achievement and the circumstances that led to his unique part in it.


Author(s):  
Marcus Gallagher-Jones ◽  
Jose A. Rodriguez ◽  
Jianwei Miao

AbstractIn 1912, Max von Laue and collaborators first observed diffraction spots from a millimeter-sized crystal of copper sulfate using an X-ray tube. Crystallography was born of this experiment, and since then, diffraction by both X-rays and electrons has revealed a myriad of inorganic and organic structures, including structures of complex protein assemblies. Advancements in X-ray sources have spurred a revolution in structure determination, facilitated by the development of new methods. This review explores some of the frontier methods that are shaping the future of X-ray diffraction, including coherent diffractive imaging, serial femtosecond X-ray crystallography and small-angle X-ray scattering. Collectively, these methods expand the current limits of structure determination in biological systems across multiple length and time scales.


2004 ◽  
Vol 22 (3) ◽  
pp. 285-288 ◽  
Author(s):  
KAZUTAKA G. NAKAMURA ◽  
YOICHIRO HIRONAKA ◽  
HIDETAKA KAWANO ◽  
HIROAKI KISHIMURA ◽  
KEN-ICHI KONDO

Ultrashort pulsed hard X rays are generated by focusing an intense femtosecond laser beam onto metal targets. Kαemissions are obtained from a Cu target. Picosecond time-resolved X-ray diffraction is performed to investigate structural dynamics of laser-shocked semiconductors using the laser plasma X-ray pulses. Lattice deformation associated with shock-wave propagation is directly observed. Evolution of strain profiles inside the crystal is determined without disturbance from the time-resolved X-ray diffraction patterns.


Author(s):  
D. Sayre

Single-particle X-ray diffraction is an extension of X-ray crystallography which allows the specimen to be any small solid-state bounded object; in Shapiroet al.[Proc. Natl Acad. Sci. USA(2005),102, 15343–15346] and Thibaultet al.[Acta Cryst.(2006), A62, 248–261], the reader can find descriptions of a recent StonyBrook/Berkeley/Cornell two-dimensional imaging of a yeast cell by this technique. Our present work is aimed at extending the technique to the three-dimensional imaging of a cell. However, the usual method of doing that, namely rotating the specimen into many orientations in the X-ray beam, has not as yet given sufficiently good three-dimensional diffraction data to allow the work to go forward, the largest problem being the difficulty of preventing unwanted levels of change in the specimen through the extended exposure to a hostile environment of X-rays and, in some cases, high vacuum and/or extreme cold. The present paper discusses possible methods of dealing with this problem.


Author(s):  
Sosale Chandrasekhar

The origins of the molecular-chiral homogeneity that is the very basis of life remain a tantalizing mystery. Molecular chirality itself is manifest in its interaction with radiation, particularly as optical activity, although an intriguing alternative technique based in X-ray crystallography is being increasingly employed. Thus, X-ray diffraction with anomalous dispersion is currently believed to lead to the absolute configuration of a stereogenic center, the ultimate goal of structural chemistry. However, despite its apparently unerring consistency, the fundamental basis of the anomalous dispersion technique is itself enigmatic. This is because it is unclear how the technique not only distinguishes two enantiomeric lattices but also assigns the absolute configuration: all, apparently, in the absence of an external chiral influence! Indeed, as argued previously, it is highly likely that the technique succeeds because the X-rays employed are circularly polarized, itself a possible consequence of parity violation. All the same, the question of how the absolute configuration is assigned remains, as the chiral sense of the putative circular polarization of the X-rays is unknown. It is argued herein that the anomalous dispersion method is essentially based in the chirality of X-rays that must have entered–although unbeknownst as such–into the calculations leading to the absolute configuration. In fact, the enigma surrounding the anomalous dispersion method derives from uncertainties concerning the theory of X-ray diffraction itself, thus leading to the apparently inescapable conclusion that both methods are essentially empirical — but without detracting from the brilliance of the scientific achievements that led to these methods.          


Author(s):  
W. Z. Chang ◽  
D. B. Wittry

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.


1998 ◽  
Vol 5 (3) ◽  
pp. 967-968 ◽  
Author(s):  
Keiichi Hirano ◽  
Atsushi Momose

The phase shift of forward-diffracted X-rays by a perfect crystal is discussed on the basis of the dynamical theory of X-ray diffraction. By means of a triple Laue-case X-ray interferometer, the phase shift of forward-diffracted X-rays by a silicon crystal in the Bragg geometry was investigated.


Author(s):  
Matthew Wilding ◽  
Colin Scott ◽  
Thomas S. Peat ◽  
Janet Newman

The NAD-dependent malonate-semialdehyde dehydrogenase KES23460 fromPseudomonassp. strain AAC makes up half of a bicistronic operon responsible for β-alanine catabolism to produce acetyl-CoA. The KES23460 protein has been heterologously expressed, purified and used to generate crystals suitable for X-ray diffraction studies. The crystals belonged to space groupP212121and diffracted X-rays to beyond 3 Å resolution using the microfocus beamline of the Australian Synchrotron. The structure was solved using molecular replacement, with a monomer from PDB entry 4zz7 as the search model.


Crystals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 273 ◽  
Author(s):  
José Brandão-Neto ◽  
Leonardo Bernasconi

Macromolecular crystallography at cryogenic temperatures has so far provided the majority of the experimental evidence that underpins the determination of the atomic structures of proteins and other biomolecular assemblies by means of single crystal X-ray diffraction experiments. One of the core limitations of the current methods is that crystal samples degrade as they are subject to X-rays, and two broad groups of effects are observed: global and specific damage. While the currently successful approach is to operate outside the range where global damage is observed, specific damage is not well understood and may lead to poor interpretation of the chemistry and biology of the system under study. In this work, we present a phenomenological model in which specific damage is understood as the result of a single process, the steady excitation of crystal electrons caused by X-ray absorption, which acts as a trigger for the bulk effects that manifest themselves in the form of global damage and obscure the interpretation of chemical information from XFEL and synchrotron structural research.


2003 ◽  
Vol 81 (7) ◽  
pp. 825-831 ◽  
Author(s):  
Chunlin Ma ◽  
Qin Jiang ◽  
Rufen Zhang

The new organotin compound, Ph2Sn(Cl)[S(C7H3N2O2S)]·[(C7H3N2O2S)OEt], assembled by an intermolecular aromatic benzothiazole–benzothiazole π-π stacking interaction, has been synthesized by the reaction of diphenyltin dichloride with 2-mercapto-6-nitrobenzothiazole. The title compound was characterized by elemental, IR, 1H NMR, and X-ray crystallography analyses. Single-crystal X-ray diffraction data reveals that the title compound has two different molecular components. The component Ph2Sn(Cl)[S(C7H3N2O2S)] has a pentacoordinate tin, which further forms an infinite one-dimensional chain by intermolecular non-bonded Cl···S interactions, resulting in an intercalation lattice that holds (C7H3N2O2S)OEt molecules. The formation of the molecule (C7H3N2O2S)OEt as well as its intercalated mechanism has also been discussed.Key words: organotin, assemble, π-π stacking interaction, 2-mercapto-6-nitrobenzothiazole, non-bonded interaction, crystal structure.


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