Volume 06, No.3
May issue 2001
1. SPring-8の現状／PRESENT STATUS OF SPring-8
The Experiments in the 6th Research Period (2000B) at the Public Beamlines of SPring-8
Call for the Beam Time Application for the Public Beamlines at SPring-8
Reorganization of the structure in the JASRI’s Synchrotron Radiation Research Laboratory
2. 共用ビームライン／PUBLIC BEAMLINE
3. その他のビームライン／OTHER BEAMLINES
4. 最近の研究から／FROM LATEST RESEARCH
Characterization of InGaAsP Selective- growth Layers Using High Resolution Microbeam x-ray Diffraction
ＮＥＣ基礎研究所 Fundamental Research Laboratories, NEC Corporation、ＮＥＣ関西 化合物デバイス統括部 Compound Semiconductor Device Division, NEC Kansai Limited、姫路工業大学 理学部 Faculty of Science, Himeji Institute of Technology
- We have succeeded in developing the high-resolution microbeam x-ray diffraction method to define optical devices. Using the method, the lattice constants of quaternary alloy (InGaAsP) compound semiconductors selectively grown in microscopic regions measuring 1.7 µm in width were accurately measured. As a result, it is possible to define the composition of the selectively grown InGaAsP layers with roughly 100 times more accuracy than when using traditional technologies.
大阪大学 蛋白質研究所 Institute for Protein Research, Osaka University
- Photosynthetic electron transfer is a key reaction, which makes green plants get the reductive power to grow. About 20 years ago, the first structure of a plant-type ferredoxin, a photosynthetic electron carrier protein, has bee reported. Many biochemists and plant physiologists have been studying the interaction site of ferredoxin based on this 3D structure. After the crystal structure of ferredoxin-NADP+ reductase, a partner protein of ferredoxin, has been reported in 1991, further experiments, including computer modeling and continuous mutational experiments, of this protein-protein interaction have been done extensively. Here we determined the first 3D structure of this electron transfer complex from maize leaf. We think that the structural information of this complex is consistent with previous biochemical and biophysical reports and conclude the precise interaction model.
（財）高輝度光科学研究センター 放射光研究所 JASRI Research Sector、総務省 通信総合研究所 関西先端研究センター Kansai Advanced Research Center, Communications Research Laboratory、（財）高輝度光科学研究センター 放射光研究所 JASRI Research Sector、理化学研究所 播磨研究所 RIKEN Harima Institute
- X-ray diffraction/scattering techniques using synchrotron radiation offer a wide range of applications to biological sciences. Protein crystallography is the best-known example. The lesser-known but equally important applications include small-angle scattering and fiber diffraction. Unlike protein crystallography, these techniques can be applied to proteins or protein assemblies functioning under physiological conditions. Here we briefly describe what can be achieved by using the fiber diffraction technique using synchrotron radiation, with an example of our own recent results on the contractile proteins in muscle fiber.
高エネルギー加速器研究機構 物質構造科学研究所 Institute of materials structure science, High energy accelerator research organization
- We have succeeded in observing nuclear excitation by electron transition (NEET) on 197Au by a new method. Monochromatic x-rays of BL09XU were used to ionize the K shell of gold atoms. The internal-conversion electrons emitted from excited nuclei were detected with the time spectroscopy using a silicon avalanche photodiode detector. At a photon energy of 80.989 keV, higher than the Au K-edge, the NEET probability on 197Au was determined from a comparison of the event rates between the NEET and the nuclear resonance at 77.351 keV.
5. 研究会等報告／WORKSHOP AND COMMITTEE REPORT
Activities of the SPring-8 Advisory Committee and the Others in the 2000 Fiscal Year