Flash induced XANES spectroscopy for the Ca‐depleted Mn‐cluster in the photosynthetic O2‐evolving enzyme
- 6 September 1993
- journal article
- Published by Wiley in FEBS Letters
- Vol. 330 (1), 28-30
- https://doi.org/10.1016/0014-5793(93)80912-e
Abstract
Flash-induced changes of the Mn K-edge absorption spectra have been studied in the oxygen-evolving complex depleted of Ca. The Mn K-edge energy for the Ca-depleted S1-state was lower by 1.5 eV than that for the normal S1-state. The K-edge energy upshifted by 1 eV after one flash, indicative of an oxidation of Mn. After two flashes, the K-edge was elevated as well by 0.4 eV, and then reached a steady-state high level after continuous illumination where the K-edge energy was higher by 0.9 eV than that after one flash. The results indicate that the Mn-cluster and/or its direct ligand could be oxidized up to two electrons but further events are blocked.Keywords
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