Visualization of Coulomb potential by electron crystallography

2014 Fiscal Year Final Research Report

• Project/Area Number: 24657111
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Biophysics
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: YONEKURA Koji 独立行政法人理化学研究所, 放射光科学総合研究センター, 准主任研究員 (50346144)
• Co-Investigator(Kenkyū-buntansha): MAKI Saori (YONEKURA Saori) 独立行政法人理化学研究所, 放射光科学総合研究センター, 研究員 (20513386)
• Co-Investigator(Renkei-kenkyūsha): TOYOSHIMA Chikashi 東京大学, 分子細胞生物学研究所, 教授 (70172210)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 構造生物学 / 結晶構造解析 / 電子顕微鏡 / 膜蛋白質 / 超分子複合体 / Ca2+-ATPase / カタラーゼ

Outline of Final Research Achievements

Electron crystallography has the potential to analyze crystals of membrane proteins and macromolecular complexes too small or too thin for X-ray crystallography, as electrons are scattered 4 - 5 orders of magnitude more strongly than X-rays. Electron crystallography yields Coulomb potential maps, rather than electron density maps as X-rays do, providing information on charged states of amino-acids and metals. We presented such Coulomb potential maps at 3.4 and 3.2 Angstrom resolution, respectively, of calcium-ATPase and catalase obtained from crystals of just a few layers thick. These maps demonstrate that it is indeed possible to build atomic models from such crystals and charge information is included, often critical in understanding protein function.

Free Research Field

生物学