Asymmetric electron transfer in photosynthetic reaction centers

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H03217
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 43040:Biophysics-related
• Research Institution: The University of Tokyo
• Principal Investigator: Ishikita Hiroshi 東京大学, 先端科学技術研究センター, 教授 (00508111)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 人工光合成 / プロトン移動 / 電子移動 / タンパク質 / X線結晶構造解析 / 水分解酸素発生

Outline of Final Research Achievements

A theoretical chemical study on electron transfer in photosynthetic reaction center proteins was conducted. In type-I reaction centers, the redox potentials of two electron transfer pathways mediated by chlorophyll in the heliobacteria reaction center (HbRC) and the reaction center derived from green sulfur bacteria (GsbRC) were elucidated. Despite all being called type I reaction centers, including photosystem I (PSI), it was revealed that the redox potentials, specifically the redox potentials between cofactors, differ significantly among them. This finding was published in a paper. Additionally, research on iron-sulfur clusters was carried out, and the results were also published in papers.

Free Research Field

生物物理

Academic Significance and Societal Importance of the Research Achievements

紅色光合成細菌の反応中心（PbRC）、Photosystem II（PSII）、Photosystem I（PSI）では、光励起・電荷分離反応を介してエネルギー変換反応を行う。PbRC, PSIIにおける「（構造の）対称性の中における（電子の振る舞いの）非対称性」という疑問は、「PbRC三次元構造の決定」（ノーベル化学賞、1988年）によって鮮明に打ち出された。数年後のMarcusによる「電子移動反応理論への貢献」（ノーベル化学賞、1992年）といった有用な理論の出現もあった。本研究の結果は、これら基礎自然科学の長年の問いへの分子化学の観点からの解となる。