Shooting Molecular Movies of Enzyme Reactions

2023 Fiscal Year Final Research Report

• Project Area: Non-equilibrium-state molecular movies and their applications
• Project/Area Number: 19H05780
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Complex systems
• Research Institution: Tottori University
• Principal Investigator: Nagano Shingo 鳥取大学, 工学研究科, 教授 (60286440)
• Co-Investigator(Kenkyū-buntansha): 中津 亨 和歌山県立医科大学, 薬学部, 教授 (50293949) ; 溝端 栄一 大阪大学, 大学院工学研究科, 講師 (90571183)
• Project Period (FY): 2019-06-28 – 2024-03-31
• Keywords: 高速分子動画 / ディールスアルダー反応 / 発光タンパク質 / Rubisco

Outline of Final Research Achievements

Research was conducted on various targets to visualize the reaction processes of enzymes and proteins as molecular movies. From the molecular dynamics simulations and the substrate-free crystal structures of Dieals-Alderases, Phm7 and Fsa2, we proposed a substrate binding mode that can explain the stereoselective reaction mechanism of the enzymes, and confirmed its accuracy with crystal structures of the methylated product-bound form of Fsa2. The order and position of the Ca2+ binding that induces the luminescence of Aequorin were also clarified. Furthermore, we determined the structure of the active and ligand-free form of Rubisco and showed that this structure is distinct from both the open and closed forms of the enzymes known so far.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

分子シミュレーションでは推定が困難なタンパク質・酵素の構造変化を実験的に捉えることは生命科学において今後ますます重要性を増す。本研究では，目標とした酵素反応の過程を可視化するには至らなかったものの，そのゴールに向けて乗り越えるべき課題，例えば試料調製やビームラインでの試料の取り扱い，時分割構造解析のデータ測定などを明らかにし，それらのいくつかについて乗り越えることができた。本研究で得られた技術と経験が今後のXFELを用いた時分割構造解析に向けた確かな礎となるであろう。