The first room‐temperature X‐ray absorption spectra of higher oxidation states of the tetra‐manganese complex of photosystem II

FEBS Letters

Grabolle, Markus¹  Dau, Holger¹  Haumann, Michael¹  Neisius, Thomas² 

[1] Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin,Germany;European Synchrotron Radiation Facility, BP. 220, 38043 Grenoble Cedex,France

关键词: Bio-X-ray absorption spectroscopy;    Metalloenzyme;    Photosynthesis;    Manganese complex;    Oxygen evolution;    EXAFS;    extended X-ray absorption fine-structure;    FT;    Fourier transform;    Mn;    manganese;    PSII;    photosystem II;    Si;    oxidation state of the Mn complex;    XAS;    X-ray absorption spectroscopy;   

DOI  :  10.1016/S0014-5793(02)02237-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The manganese (Mn) complex of photosystem II catalyzes water oxidation. For the first time, its advancement through the reaction cycle was monitored by time-resolved X-ray absorption measurements at the Mn K-edge at room temperature. The complex was stepped through its four oxidation states by nano-second-laser flashes applied to samples exposed to the X-ray beam. Time courses of the X-ray fluorescence intensity were recorded during a flash sequence. Extended X-ray absorption fine-structure spectra were recorded with the S₁, S₂, and S₃ oxidation states highly populated. The room temperature data is compatible with the formation of a third di-μ-oxo bridge between two Mn atoms upon the S₂→S₃ transition.

【 授权许可】

Unknown