Volume 04, No.4

1. ハイライト／HIGHLIGHT

兵庫県ビームラインの利用状況
Hyogo Beamline Operating Status

岩崎　英雄　IWASAKI Hideo

（財）ひょうご科学技術協会　Hyogo Science and Technology Association

Pages 1 - 4 Download PDF (34.42 KB)

2. SPring-8の現状／PRESENT STATUS OF SPring-8

SPring-8運転・利用状況
SPring-8 Operational News

（財）高輝度光科学研究センター　計画管理グループ　JASRI Planning Management Section

Pages 5 - 6 Download PDF (15.39 KB)

3. 共用ビームライン／PUBLIC BEAMLINE

平成10、11年度整備アンジュレータビームライン
Undulator Beamlines Constructed in the 1998 and 1999 Fiscal Years

後藤　俊治　GOTO Shunji

（財）高輝度光科学研究センター　放射光研究所　ビームライン部門　JASRI Beamline Division

Pages 7 - 15 Download PDF (744.75 KB)

4. 原研･理研･R&Dビームライン／JAERI･RIKEN･R&D BEAMLINE

産業界専用IDビームライン（BL16XU）の現状
Present Status of Industrial Consortium ID Beamline for Materials Research

平井　康晴　HIRAI Yasuharu

㈱日立製作所　基礎研究所　Advanced Research Laboratory, Hitachi, Ltd.

Abstract: Beamline BL16XU at SPring-8, together with its sister beamline BL16B2, was designed and constructed by an industrial consortium of 13 companies to characterize various materials developed for industrial purposes. 　The main experiments are fluorescence X-ray analysis and X-ray diffraction using X-ray beam of several tens-µm to sub-mm size. Optics for several-µm X-ray beam will also be available for characterization of sophisticated thin film devices and new fine structured materials.

Pages 16 - 19 Download PDF (411.76 KB)

産業界専用BMビームライン（BL16B2）の現状
Present Status of Industrial Consortium BM Beamline for Materials Research

泉　弘一　IZUMI Koichi

日本電気㈱　基礎研究所　Fundamental Research Laboratories, NEC Corporation

Abstract: Beamline BL16B2, together with its sister beamline BL16XU, is designed and constructed by an industrial consortium of 13 companies to characterize various materials developed for industrial purposes. 　The main experiments on this beamline are XAFS and X-ray topography, and in some cases X-ray diffraction and X-ray fluorescent analysis. The energy range from the titanium K-edge to the thulium K-edge is covered.

Pages 20 - 22 Download PDF (756.82 KB)

BL29XUの試運転状況
Current Status of RIKEN BL29XU

玉作　賢治　TAMASAKU Kenji

理化学研究所　X線干渉光学研究室　The Institute of Physical and Chemical Research (RIKEN)

Pages 23 - 27 Download PDF (248.46 KB)

生体超分子複合体構造解析ビームライン（BL44XU）の建設状況
Construction of Macromolecular Assemblies (BL44XU)

山下　栄樹　YAMASHITA Eiki、月原　冨武　TSUKIHARA Tomitake

大阪大学　蛋白質研究所　Institute for Protein Research, Osaka University

Pages 28 - 30 Download PDF (535.18 KB)

5. 最近の研究から／FROM LATEST RESEARCH

Capacitance-XAFS 不均一系のXAFSへの新しいアプローチ
Capacitance-XAFS: A New Approach to XAFS of Heterogeneous System

石井　真史　ISHII Masashi

（財）高輝度光科学研究センター　放射光研究所　利用促進部門　JASRI Experimental Facilities Division

Abstract: In order to analyze the local structure of heterogeneous system, the 'capacitance-XAFS' by measuring the x-ray photon-energy dependence of the capacitance of a Schottky barrier diode is proposed. Since the capacitance is sensitive to the localized electron in the deep level, dropping of the electron into a core hole arising from X-ray absorption of the atom in the deep level, not the bulk atom, increases the capacitance. The site-selectivity of the capacitance XAFS is successfully applied to AlGaAs:Se system. Several applications of the capacitance-XAFS to heterogeneous system, such as the interface XAFS, are introduced.

Pages 31 - 34 Download PDF (171.88 KB)

水素酸化還元酵素のＸ線構造化学
X-ray Structural Study for Hydrogenase

樋口　芳樹　HIGUCHI Yoshiki

京都大学大学院　理学研究科　Division of Chemistry, Graduate School of Science, Kyoto University

Abstract: Hydrogenases are enzymes which are responsible for the hydrogen metabolism in bacteria. The active site of the [NiFe] hydrogenase has been reported as a hetero binuclear Ni-Fe complex with four non-protein ligands. The Ni atom is coordinated by four sulfur atoms of cysteinyl residues, and two of them coordinate to the Fe atom making the bridges between two metal atoms. The four non-protein ligands of the [NiFe] hydrogenase from D. vulgaris Miyazaki F in the oxidized form were assigned as SO, CO, CN and S. In contrast, those in the hydrogenase from D. gigas were reported as CO, CN, CN and O. Recently we found that the hydrogenase of Miyazaki strain liberated H₂S upon reduction with H₂ in the presence of its electron carrier. The x-ray crystal structure of the H₂-reduced form of the Miyazaki enzyme at 1.4 Å resolution was successfully solved and refined to a crystallographic R-factor of 21.8 %. Though the structure was almost identical to that of the oxidized form, the non-protein monatomic bridge which was observed between the Ni and Fe atoms in the oxidized form disappeared. Considering the experimental results mentioned above, we have concluded that the monatomic bridge ligand between the Ni and Fe atoms must not be a oxygen species but a sulfur species, and this ligand should be removed as H₂S when the enzyme is activated upon reduction with H₂. This sulfur bridging ligand may have an essential key role for the catalytic cycle of the [NiFe] hydrogenase.