3P272 Structural coupling of Ca^<2+> with the oxygen evolving Mn cluster: FTIR analysis by Sr^<2+> substitution
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چکیده
منابع مشابه
Calcium EXAFS establishes the Mn-Ca cluster in the oxygen-evolving complex of photosystem II.
The proximity of Ca to the Mn cluster of the photosynthetic water-oxidation complex is demonstrated by X-ray absorption spectroscopy. We have collected EXAFS data at the Ca K-edge using active PS II membrane samples that contain approximately 2 Ca per 4 Mn. These samples are much less perturbed than previously investigated Sr-substituted samples, which were prepared after Ca depletion. The new ...
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Photosystem II (PSII), which catalyzes photosynthetic water oxidation, is composed of more than 20 subunits, including membrane-intrinsic and -extrinsic proteins. The PSII extrinsic proteins shield the catalytic Mn4CaO5 cluster from the outside bulk solution and enhance binding of inorganic cofactors, such as Ca(2+) and Cl(-), in the oxygen-evolving center (OEC) of PSII. Among PSII extrinsic pr...
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Nearly all of the dioxygen which animals and aerobic bacteria use during respiration originates from the photosynthetic oxygen evolving complex (OEC) which is found in the chloroplast thylakoid membranes of higher plants and algae. Four specifically bound Mn are required for OEC activity [l]. These manganese do not exhibit the six line epr spectrum which is characteristic of Mn(IIj in solution,...
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ژورنال
عنوان ژورنال: Seibutsu Butsuri
سال: 2005
ISSN: 0582-4052,1347-4219
DOI: 10.2142/biophys.45.s271_4