Since the first crystal structure determination of protein by J. C. Kendrew in 1959, protein crystallography has been playing the leading role in the structural biology by various technology developments. Especially the utilization of synchrotron radiation from the 1990s brought innovative progress in this field on the data quality and the phasing method and had expanded the sample targets including membrane proteins and supra-molecular complexes. Here we will describe the outline and the future prospects of the protein crystallography from the role of synchrotron radiation and SPring-8.
SPring-8 has played an important role in chemical research by providing detailed crystal structure analyses. Thanks to introducing the latest diffractometers, developments of methodologies, and devoted efforts of beamline scientists, chemists have enjoyed their own science by using SPring-8. This report presents several examples of outstanding research in chemistry generated by the use of SPring-8 in the last 10 years and also sheds light on promising methodologies for chemical research in powder diffraction measurements developed in SPring-8.
Large Debye-Scherrer camera using imaging plate detector enabled us to acquire high resolution and high counting statistic powder diffraction data. Many researches have been achieved since it was launched at BL02B2 in SPring-8. In recent years, in situ measurements, e.g. gas adsorption, chemical reaction, crystal growth, etc. can be conducted by the introduction of MYTHEN detectors and the development of apparatuses to realize special sample environment. In this paper, the upgrade of diffraction measurement system and some of the outstanding research achievements at BL02B2 are shown.
The surface X-ray diffraction method was started in mid 1980s and has been developed in tandem with synchrotron facility. It takes advantage of many characteristics of synchrotron x-ray, such as low emittance, high monochromaticity and high intensity. Many surface/interface phenomena involve atomic migration, whose characteristic time scale is on the order of millisecond or slower; therefore, time resolved measurement and coherent surface diffraction should be useful. The analysis of the surface diffraction requires high computational resource, thus development of software is also important. Recent development of surface x-ray diffraction technique in the world is summarized.
SPring-8 has many beamlines equipped with Large-Volume Presses and Diamond Anvil Cell-type high-pressure apparatuses, and various high-pressure experiments have been performed. In this paper, we introduce the overview of two public beamlines BL04B1 and BL10XU, and recent research results from these beamlines.
Coherent X-ray diffraction imaging(CDI)is a lens-less imaging technique that can visualize the structures of non-crystalline specimens with micro- to sub-micrometer dimensions. In the past ten years, two experimental techniques in CDI, cryogenic CDI tomography and atmospheric ptychography has been developed and established at SPring-8. Here we review these experimental techniques and the achievement to discuss future prospect of CDI at future synchrotron facilities, that provide X-rays with high spatial coherence.
Structural analysis of disordered materials is still very challenging due to the absence of translational symmetry. Diffraction patterns from disordered materials are very broad and provide information only about pair correlations. Brilliant high-energy X-rays from third-generation synchrotron radiation sources, like SPring-8, allow us to measure high-quality diffraction data for disordered materials from ambient to high temperature and/or high pressure. Such data have significantly improved our capabilities to grasp the ‘order within disorder’. Here, we describe the progress in terms of the instrumentation for using high-energy X-rays at SPring-8 over the last 20 years. Advanced methods of data analysis, that help to understand structural ordering hidden in pairwise correlations of disordered materials, are also introduced.
Recent progress on operando three-dimensional XAFS imaging of polymer electrolyte fuel cell, which is one of clean and efficient energy systems, is reported. The combination of operando XAFS and X-ray CT imaging provides us the three-dimensional images of morphology, catalyst distribution, and the chemical state of metal catalysts in PEFC.
Chromatin is a highly organized complex of genomic DNA and proteins in eukaryotic cells. Fundamental unit of chromatin is nucleosome composed of histone octamer and approximately 150 base pairs of DNA. The higher-order conformation of chromatin is involved in important genomic events such as replication, transcription, recombination, and repair. Recently various structures chromatin have been determined by cryo-electron microscopy (cryo-EM). Based on our cryo-EM studies, in this article, we introduce current structures of chromatin determined by cryo-EM.
The iota toxin produced by Clostridium perfringens type E is a binary toxin comprising two independent polypeptides:Ia, an ADP-ribosyltransferase, and Ib, which is involved in cell binding and translocation of Ia across the cell membrane. Binary toxin family includes C. perfringens iota toxin, C. difficile CDT, C. spiroforme CST, C. botulinum C2, and B. anthracis anthrax toxin. Here we introduce the binary toxin complex structures using single-particle Cryo-EM structural analysis and the structural basis of toxin translocation system.