In:
Philosophical Transactions of the Royal Society B: Biological Sciences, The Royal Society, Vol. 363, No. 1494 ( 2008-03-27), p. 1139-1147
Abstract:
The application of high-resolution X-ray spectroscopy methods to study the photosynthetic water oxidizing complex, which contains a unique hetero-nuclear catalytic Mn 4 Ca cluster, is described. Issues of X-ray damage, especially at the metal sites in the Mn 4 Ca cluster, are discussed. The structure of the Mn 4 Ca catalyst at high resolution, which has so far eluded attempts of determination by X-ray diffraction, X-ray absorption fine structure (EXAFS) and other spectroscopic techniques, has been addressed using polarized EXAFS techniques applied to oriented photosystem II (PSII) membrane preparations and PSII single crystals. A review of how the resolution of traditional EXAFS techniques can be improved, using methods such as range-extended EXAFS, is presented, and the changes that occur in the structure of the cluster as it advances through the catalytic cycle are described. X-ray absorption and emission techniques (XANES and Kβ emission) have been used earlier to determine the oxidation states of the Mn 4 Ca cluster, and in this report we review the use of X-ray resonant Raman spectroscopy to understand the electronic structure of the Mn 4 Ca cluster as it cycles through the intermediate S-states.
Type of Medium:
Online Resource
ISSN:
0962-8436
,
1471-2970
DOI:
10.1098/rstb.2007.2209
Language:
English
Publisher:
The Royal Society
Publication Date:
2008
detail.hit.zdb_id:
1462620-2
SSG:
12
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