کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5403923 | 1505931 | 2007 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Low-energy absorption and luminescence of higher plant photosystem II core samples
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
The charge-separating state of PSII has been recently assigned as a homogeneously broadened band peaking at 705Â nm. The possibility of observing emission due to luminescence from the charge-separating state was investigated. Emission from the charge-separating state is predicted to be both broad and substantially Stokes shifted. Our PSII cores show an easily observable and broad emission peaking near 735Â nm when excited at 707Â nm and beyond for temperatures below 100Â K as well as the well-known F685 and F695Â nm emission when excited at 633Â nm. However, the 735Â nm emission bears a close correspondence to that previously reported for the light harvesting pigment of photosystem I (PSI), LHCI-730, and we attribute our observed emission to a minor contamination of our sample with this protein. High sensitivity circular dichroism (CD) spectra establish that LHCI and/or PSI contamination of our samples does not contribute significantly to the absorption seen in the 700-730Â nm region. Furthermore, systematic illumination-induced absorption changes seen in this region are shown to quantitatively track with charge separation and the subsequent secondary acceptor plastoquinone (QA) acceptor anion formation. These results confirm that absorption in the 700-730Â nm region is associated with the reaction centre of active PSII.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volumes 122â123, JanuaryâApril 2007, Pages 284-287
Journal: Journal of Luminescence - Volumes 122â123, JanuaryâApril 2007, Pages 284-287
نویسندگان
Joseph L. Hughes, Paul J. Smith, Ron J. Pace, Elmars Krausz,