Theoretical study on biomolecular functions: Effects of conformational fluctuations and changes

2021 Fiscal Year Final Research Report

• Project/Area Number: 16H02254
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Institute for Molecular Science
• Principal Investigator: SAITO SHINJI 分子科学研究所, 理論・計算分子科学研究領域, 教授 (70262847)
• Project Period (FY): 2016-04-01 – 2021-03-31
• Keywords: 構造変化 / 生体分子系機能 / 励起エネルギー移動 / 概日リズム / 反応速度 / 動的乱れ

Outline of Final Research Achievements

In biomolecules and liquids, conformations fluctuate and change over a wide range of spatiotemporal scales. In this project, we conducted theoretical studies on how chemical reactions and conformational changes proceed in biomolecular systems and how biomolecular functions are brought about under fluctuations. As a result, we revealed the presence of heterogeneous conformational changes and important prepared structures before reaction. We have also clarified the molecular mechanism of efficient excitation energy transfer in photosynthetic bacteria. In addition, we conducted theoretical studies on the dynamics of water and ionic aqueous solutions. As a result, we found a new dynamical transition at a very low temperature and revealed the low glass transition temperature of water. Furthermore, we investigated the molecular mechanism of ion and concentration dependence of collective orientation relaxation of water in aqueous solutions.

Free Research Field

物理化学

Academic Significance and Societal Importance of the Research Achievements

反応に関して、タンパク質の折れ畳みを例に構造変化の時間分布が従来の一次元理論では記述できないこと、異性化反応を例に反応前に構造変化に重要な構造励起状態の存在等を明らかにした。生体機能に関しては、光合成細菌における効率的励起エネルギー移動の分子機構を解明した。さらに、水に関する研究において、これまで見出されていなかった状態変化や低いガラス転移温度の起源等を解明した。これらの成果として、2018, 2019年におけるJ. Chem. Phys.のLiquids, Glasses, and Crystals分野のベスト論文に2報の論文が選ばれる等、国際的にも本研究課題の学術的意義が認知されている。