Understanding the Redox Reactions of a High-potential Iron-sulfur Protein through High-Resolution X-ray and Neutron Crystallography

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K22642
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0701:Biology at molecular to cellular levels, and related fields
• Research Institution: Tokyo Medical and Dental University (2021-2023); National Institutes for Quantum and Radiological Science and Technology (2020)
• Principal Investigator: Hanazono Yuya 東京医科歯科大学, 難治疾患研究所, 准教授 (00750465)
• Project Period (FY): 2020-09-11 – 2024-03-31
• Keywords: 電子伝達タンパク質 / 精密構造解析 / 中性子構造解析 / X線構造解析

Outline of Final Research Achievements

The structural analysis of high-potential iron-sulfur protein derived from Thermochromatium tepidum was performed by combining 0.66 Å resolution X-ray diffraction data and 1.2 Å resolution neutron diffraction data. For the first time, it was successful to refine the coordinates of hydrogen atoms in the protein structure without restraints. Experimentally, it was demonstrated that amide protons, which are thought to exist in the peptide plane, are actually influenced by the surrounding electronic state, showing variability in deviation from planarity. Additionally, the deviation of the amide protons from the plane is also involved in redox functions, suggesting that differences in the peptide planes around the iron-sulfur clusters in oxidized and reduced states contribute to the stabilization of charge states.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

本研究は、高電位鉄硫黄タンパク質構造を、X線および中性子線回折データを用いて高精度で解析し、水素原子の位置を含めた詳細な構造を明らかにしました。この成果は、タンパク質の酸化還元反応のメカニズムを明らかにし、新薬開発や生物工学における応用に貢献します。社会的には、これにより病気の治療法の開発や環境に優しいエネルギー生成方法の研究が進む可能性があります。