Abstract
In order to understand the organization of the PSI core antenna and to interpret results obtained from studies of the temperature and wavelength dependence of energy transfer and trapping in the PSI particles, we have constructed a model for PSI in which spectral heterogeneity is considered via a self-consistent approach based on Forster transport. The temperature dependence of the absorption and emission spectra of the individual Chl molecules in the protein matrix is calculated based on a model Hamiltonian which includes a phonon contribution. Time and wavelength resolved kinetics of PSI at different temperatures are investigated by means of two-dimensional lattice models. We conclude that wavelength-dependent fluorescence decay kinetics result only when two or more bottlenecks exist in the energy transfer and trapping process. A single trap or several pseudo-traps with spectrally identical environments do not lead to wavelength dependent decays. Simple funnel arrangements of the spectral types can be ruled out. At least one pigment with energy lower than the photochemical trap located close to the reaction center is required to produce the trends of the fluorescence lifetimes observed experimentally. The remainder of the core antenna is consistent with a random arrangement of spectral types.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Butler W. L., Kitajima M. Energy transfer between photosystem II and photosystem I in chloroplasts. Biochim Biophys Acta. 1975 Jul 8;396(1):72–85. doi: 10.1016/0005-2728(75)90190-5. [DOI] [PubMed] [Google Scholar]
- Fitch C. P., Rapoza P. A., Owens S., Murillo-Lopez F., Johnson R. A., Quinn T. C., Pepose J. S., Taylor H. R. Epidemiology and diagnosis of acute conjunctivitis at an inner-city hospital. Ophthalmology. 1989 Aug;96(8):1215–1220. doi: 10.1016/s0161-6420(89)32749-7. [DOI] [PubMed] [Google Scholar]
- Holzwarth A. R. Applications of ultrafast laser spectroscopy for the study of biological systems. Q Rev Biophys. 1989 Aug;22(3):239–326. doi: 10.1017/s0033583500002985. [DOI] [PubMed] [Google Scholar]
- Owens T. G., Webb S. P., Alberte R. S., Mets L., Fleming G. R. Antenna structure and excitation dynamics in photosystem I. I. Studies of detergent-isolated photosystem I preparations using time-resolved fluorescence analysis. Biophys J. 1988 May;53(5):733–745. doi: 10.1016/S0006-3495(88)83154-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Owens T. G., Webb S. P., Mets L., Alberte R. S., Fleming G. R. Antenna size dependence of fluorescence decay in the core antenna of photosystem I: estimates of charge separation and energy transfer rates. Proc Natl Acad Sci U S A. 1987 Mar;84(6):1532–1536. doi: 10.1073/pnas.84.6.1532. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Owens T. G., Webb S. P., Mets L., Alberte R. S., Fleming G. R. Antenna structure and excitation dynamics in photosystem I. II. Studies with mutants of Chlamydomonas reinhardtii lacking photosystem II. Biophys J. 1989 Jul;56(1):95–106. doi: 10.1016/S0006-3495(89)82654-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schatz G. H., Brock H., Holzwarth A. R. Kinetic and Energetic Model for the Primary Processes in Photosystem II. Biophys J. 1988 Sep;54(3):397–405. doi: 10.1016/S0006-3495(88)82973-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Seely G. R. Energy transfer in a model of the photosynthetic unit of green plants. J Theor Biol. 1973 Jul;40(1):189–199. doi: 10.1016/0022-5193(73)90171-9. [DOI] [PubMed] [Google Scholar]
- Werst M., Jia Y., Mets L., Fleming G. R. Energy transfer and trapping in the photosystem I core antenna. A temperature study. Biophys J. 1992 Apr;61(4):868–878. doi: 10.1016/S0006-3495(92)81894-5. [DOI] [PMC free article] [PubMed] [Google Scholar]