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Energy transfer in the inhomogeneously broadened core antenna of purple bacteria : a simultaneous fit of low-intensity picosecond absorption and fluorescence kinetics

Pullerits, Tõnu LU ; Visscher, Kees J. ; Hess, Sussan LU ; Sundström, V. LU ; Freiberg, A. LU ; Timpmann, K. and van Grondelle, R. (1994) In Biophysical Journal 66(1). p.236-248
Abstract

The excited state decay kinetics of chromatophores of the purple photosynthetic bacterium Rhodospirillum rubrum have been recorded at 77 K using picosecond absorption difference spectroscopy under strict annihilation free conditions. The kinetics are shown to be strongly detection wavelength dependent. A simultaneous kinetic modeling of these experiments together with earlier fluorescence kinetics by numerical integration of the appropriate master equation is performed. This model, which accounts for the spectral inhomogeneity of the core light-harvesting antenna of photosynthetic purple bacteria, reveals three qualitatively distinct stages of excitation transfer with different time scales. At first a fast transfer to a local energy... (More)

The excited state decay kinetics of chromatophores of the purple photosynthetic bacterium Rhodospirillum rubrum have been recorded at 77 K using picosecond absorption difference spectroscopy under strict annihilation free conditions. The kinetics are shown to be strongly detection wavelength dependent. A simultaneous kinetic modeling of these experiments together with earlier fluorescence kinetics by numerical integration of the appropriate master equation is performed. This model, which accounts for the spectral inhomogeneity of the core light-harvesting antenna of photosynthetic purple bacteria, reveals three qualitatively distinct stages of excitation transfer with different time scales. At first a fast transfer to a local energy minimum takes place (approximately 1 ps). This is followed by a much slower transfer between different energy minima (10–30 ps). The third component corresponds to the excitation transfer to the reaction center, which depends on its state (60 and 200 ps for open and closed, respectively) and seems also to be the bottleneck in the overall trapping time. An acceptable correspondence between theoretical and experimental decay kinetics is achieved at 77 K and at room temperature by assuming that the width of the inhomogeneous broadening is 10–15 nm and the mean residence time of the excitation in the antenna lattice site is 2–3 ps.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
in
Biophysical Journal
volume
66
issue
1
pages
13 pages
publisher
Cell Press
external identifiers
  • pmid:8130341
  • scopus:0028118530
ISSN
0006-3495
DOI
10.1016/S0006-3495(94)80770-2
language
English
LU publication?
no
id
6303fe5c-13ef-4ca6-9fc1-37e2dcca7e2b
date added to LUP
2025-10-28 17:10:49
date last changed
2025-10-31 11:27:38
@article{6303fe5c-13ef-4ca6-9fc1-37e2dcca7e2b,
  abstract     = {{<p>The excited state decay kinetics of chromatophores of the purple photosynthetic bacterium Rhodospirillum rubrum have been recorded at 77 K using picosecond absorption difference spectroscopy under strict annihilation free conditions. The kinetics are shown to be strongly detection wavelength dependent. A simultaneous kinetic modeling of these experiments together with earlier fluorescence kinetics by numerical integration of the appropriate master equation is performed. This model, which accounts for the spectral inhomogeneity of the core light-harvesting antenna of photosynthetic purple bacteria, reveals three qualitatively distinct stages of excitation transfer with different time scales. At first a fast transfer to a local energy minimum takes place (approximately 1 ps). This is followed by a much slower transfer between different energy minima (10–30 ps). The third component corresponds to the excitation transfer to the reaction center, which depends on its state (60 and 200 ps for open and closed, respectively) and seems also to be the bottleneck in the overall trapping time. An acceptable correspondence between theoretical and experimental decay kinetics is achieved at 77 K and at room temperature by assuming that the width of the inhomogeneous broadening is 10–15 nm and the mean residence time of the excitation in the antenna lattice site is 2–3 ps.</p>}},
  author       = {{Pullerits, Tõnu and Visscher, Kees J. and Hess, Sussan and Sundström, V. and Freiberg, A. and Timpmann, K. and van Grondelle, R.}},
  issn         = {{0006-3495}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{236--248}},
  publisher    = {{Cell Press}},
  series       = {{Biophysical Journal}},
  title        = {{Energy transfer in the inhomogeneously broadened core antenna of purple bacteria : a simultaneous fit of low-intensity picosecond absorption and fluorescence kinetics}},
  url          = {{http://dx.doi.org/10.1016/S0006-3495(94)80770-2}},
  doi          = {{10.1016/S0006-3495(94)80770-2}},
  volume       = {{66}},
  year         = {{1994}},
}