One- and Two-Color Photon Echo Peak Shift Studies of Photosystem I
Citations Over Time
Abstract
Wavelength-dependent one- and two-color photon echo peak shift spectroscopy was performed on the chlorophyll Qy band of trimeric photosystem I from Thermosynechococcus elongatus. Sub-100 fs energy transfer steps were observed in addition to longer time scales previously measured by others. In the main PSI absorption peak (675-700 nm), the peak shift decays more slowly with increasing wavelength, implying that energy transfer between pigments of similar excitation energy is slower for pigments with lower site energies. In the far-red region (715 nm), the decay of the peak shift is more rapid and is complete by 1 ps, a consequence of the strong electron-phonon coupling present in this spectral region. Two-color photon echo peak shift data show strong excitonic coupling between pigments absorbing at 675 nm and those absorbing at 700 nm. The one- and two-color peak shifts were simulated using the previously developed energy transfer model (J. Phys. Chem. B 2002, 106, 10251; Biophysical Journal 2003, 85, 140). The simulations agree well with the experimental data. Two-color photon echo peak shift is shown to be far more sensitive to variations in the molecular Hamiltonian than one-color photon echo peak shift spectroscopy.
Related Papers
- → Active Oxygen Produced during Selective Excitation of Photosystem I Is Damaging Not Only to Photosystem I, But Also to Photosystem II(2001)99 cited
- → PROTEIN COMPOSITION OF SPINACH CHLOROPLASTS AND THEIR PHOTOSYSTEM I AND PHOTOSYSTEM II SUBFRAGMENTS*(1974)60 cited
- → Inactive photosystem II centers: A resolution of discrepencies in photosystem II quantitation(1990)24 cited
- → Characterisation of electron acceptors A0 and A1 in cyanobacterial Photosystem I(1987)12 cited
- [Ultrastructural localization of photosystem I and II active sites in chloroplasts in situ].(1977)