Femtosecond primary charge separation in Synechocystis sp. PCC 6803 photosystem I.

@article{Shelaev2010FemtosecondPC,
  title={Femtosecond primary charge separation in Synechocystis sp. PCC 6803 photosystem I.},
  author={I. Shelaev and F. Gostev and M. Mamedov and O. Sarkisov and V. Nadtochenko and V. Shuvalov and A. Semenov},
  journal={Biochimica et biophysica acta},
  year={2010},
  volume={1797 8},
  pages={
          1410-20
        }
}
The ultrafast (<100 fs) conversion of delocalized exciton into charge-separated state between the primary donor P700 (bleaching at 705 nm) and the primary acceptor A0 (bleaching at 690 nm) in photosystem I (PS I) complexes from Synechocystis sp. PCC 6803 was observed. The data were obtained by application of pump-probe technique with 20-fs low-energy pump pulses centered at 720 nm. The earliest absorbance changes (close to zero delay) with a bleaching at 690 nm are similar to the product of the… Expand
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References

SHOWING 1-10 OF 37 REFERENCES
Ultrafast primary processes in PS I from Synechocystis sp. PCC 6803: roles of P700 and A(0).
The excitation transport and trapping kinetics of core antenna-reaction center complexes from photosystem I of wild-type Synechocystis sp. PCC 6803 were investigated under annihilation-freeExpand
PRIMARY CHARGE SEPARATION AND ENERGY TRANSFER IN THE PHOTOSYSTEM I REACTION CENTER OF HIGHER PLANTS
Using low intensity femtosecond duration laser pulses at 708 nm, we have observed absorption transients associated with electron transfer through the primary electron acceptor A0 in the photosystem IExpand
Excitation dynamics and heterogeneity of energy equilibration in the core antenna of photosystem I from the cyanobacterium Synechocystis sp. PCC 6803.
Energy equilibration in the photosystem I core antenna from the cyanobacterium Synechocystis sp. PCC 6803 was studied using femtosecond transient absorption spectroscopy at 298 K. The photosystem IExpand
Primary light-energy conversion in tetrameric chlorophyll structure of photosystem II and bacterial reaction centers: II. Femto- and picosecond charge separation in PSII D1/D2/Cyt b559 complex
In Part I of the article, a review of recent data on electron-transfer reactions in photosystem II (PSII) and bacterial reaction center (RC) has been presented. In Part II, transient absorptionExpand
Excitonic interactions in wild-type and mutant PSI reaction centers.
TLDR
Compared the transient absorbance changes after excitation at 700, 705, and 710 nm at 20 K in several PSI preparations of Chlamydomonas reinhardtii where amino acid ligands of the primary donor, primary acceptor, or connecting chlorophylls have been mutated supports the view that the chlorophyLLs of the electron transfer chain as well as the connecting chloropylls are engaged in the observed absorbsance changes. Expand
Observation of the reduction and reoxidation of the primary electron acceptor in photosystem I.
Femtosecond transient absorption spectroscopy has been used to investigate the primary charge separation in a photosystem II deletion mutant from the cyanobacterium Synechocystis sp. PCC 6803. TheseExpand
Picosecond transient absorption spectroscopy in the blue spectral region of photosystem I.
TLDR
The picosecond transient absorption difference spectroscopy in the blue wavelength region was used to study the early electron acceptors in photosystem I, showing significant differences with similar spectra measured on longer time scales. Expand
Observation of the Excited State of the Primary Electron Donor Chlorophyll (P700) and the Ultrafast Charge Separation in the Spinach Photosystem I Reaction Center
Femtosecond transient absorption spectroscopy was applied to the photosystem I reaction center particles containing only 12−13 chlorophylls per primary electron donor chlorophyll (P700), which wereExpand
Excitation Dynamics in the Core Antenna of PS I from Chlamydomonas reinhardtii CC 2696 at Room Temperature
Photosystem I particles from a eukaryotic organism, the green alga Chlamydomonas reinhardtii CC 2696, were studied by transient hole-burning spectroscopy at room temperature. Global analysis of theExpand
Picosecond absorbance changes upon selective excitation of the primary electron donor P-700 in Photosystem I
Abstract Selective picosecond excitation of P + -700, at 710 nm, was used to study the primary processes in reaction centers in relatively intact Photosystem I particles. The transient formation ofExpand
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