News Releases & Research Results Identification of the mechanism by which the "distorted-chair" structure catalyzes oxygen molecules formation in photosynthesis: key to rational design of catalysts for artificial photosynthesis

Results of collaborative research by the study group led by Associate Professor Michihiro Suga, Associate Professor Fusamichi Akita, and Professor Jian-Ren Shen of the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Full-Time Researcher Hideo Ago of RIKEN, and others.

• Photosynthesis is initiated by the reactions of a protein complex called photosystem II to take oxygen molecules from water molecules, using light energy; however, the mechanism by which oxygen molecules are produced has not yet been identified.
• Using a type of charged particle beam called an X-ray-free-electron laser, the structure of the “distorted-chair”-shaped catalyst in photosystem II, just before forming oxygen molecules, was determined in this study.
• The study results are expected to contribute to design of a catalyst for artificial photosynthesis to split water, as well as elucidation of the mechanism by which hydrogen ions and electrons are extracted from water molecules in photosynthesis.

This R&D project was conducted with the support of Basis for Supporting Innovative Drug Discovery and Life Science Research by AMED.

The study results were published in Science, an American scientific journal, on October 17.

Suga M., et al. An oxyl/oxo mechanism for oxygen-oxygen coupling in PSII revealed by an X-ray free electron laser Science
DOI：10.1126/science.aax6998 10.1126/science.aax6998