Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10870420 | FEBS Letters | 2014 | 4 Pages |
Abstract
Femtosecond absorption spectroscopy was applied to study for the first time excitation dynamics in isolated photosystem I trimers from Arthrospira platensis, which display extremely long-wavelength absorption peaks. Pump-probe spectra observed at 77Â K in the timescale of dozens of picoseconds upon 70-fs excitation revealed two maxima near 710 and 730Â nm, which correspond to red chlorophyll forms. Bleaching at 680Â nm developed in â¼200Â fs, whereas the bleaching kinetics at 710 and 730Â nm exhibited two components with time constants of 1 and 5.5Â ps. Comparison of the kinetics of bleaching development at 710Â nm and 730Â nm with that of bleaching decay at 680Â nm indicated that both long-wavelength forms of trimers are populated mainly via direct energy transfer from bulk chlorophyll.
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Authors
Viktor Kompanets, Vladimir Shubin, Irina Terekhova, Elena Kotova, Vladimir Kozlovsky, Vladimir Novoderezhkin, Sergey Chekalin, Navasard Karapetyan, Andrei Razjivin,