| Numéro |
J. Phys. IV France
Volume 7, Numéro C2, Avril 1997
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
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|---|---|---|
| Page(s) | C2-607 - C2-610 | |
| DOI | https://doi.org/10.1051/jp4/1997112 | |
J. Phys. IV France 7 (1997) C2-607-C2-610
DOI: 10.1051/jp4/1997112
X-Ray Absorption Linear Dichroism Spectroscopy (XALDS) on the Photosystem II Manganese Complex: Radiation Damage and S1-State K-edge Spectra
H. Dau1, J. Dittmer1, L. Iuzzolino1, H. Schiller1, W. Dorner1, I. Heinze1, V. A. Sole2 and H.-F. Nolting21 FB Biologie/Botanik, Philipps-Universität, Lahnberge, 35032 Marburg, Germany
2 EMBL Hamburg Outstation, Notkestraße 85, 22603 Hamburg, Germany
Abstract
X-ray absorption spectroscopy (XAS) at the Mn K-edge is used to unravel the structure of the oxygen-evolving
manganese complex which is embedded in the Photosystem II (PS II) protein complex; measurements on multilayers of PS
II-containing membrane sheets provide angular information (XALDS). (1) By XAS and electron spin resonance (ESR) we
investigated origin and characteristics of the radiation damage which is caused by prolonged exposure to intense
synchrotron radiation. (2) By a derivative analysis of XALD-edge spectra, eight distinct transitions are resolvable (a to h).
In contrast to the transitions c to e of the edge rise, f (6562 eV) and g (6565 eV) on top of the Mn K-edge exhibit
characteristics of a formally-allowed electric dipole transition with an angle between transition dipole and membrane
normal greater (f) and smaller (g) than the magic angle (= 54.7°), respectively.
© EDP Sciences 1997