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Spectral and kinetic effects accompanying the assembly of core complexes of Rhodobacter sphaeroides

Freiberg, Arvi ; Chenchiliyan, Manoop LU ; Rätsep, Margus and Timpmann, Kõu (2016) In Biochimica et Biophysica Acta - Bioenergetics 1857(11). p.1727-1733
Abstract

In the present work, spectral and kinetic changes accompanying the assembly of the light-harvesting 1 (LH1) complex with the reaction center (RC) complex into monomeric RC-LH1 and dimeric RC-LH1-PufX core complexes of the photosynthetic purple bacterium Rhodobacter sphaeroides are systematically studied over the temperature range of 4.5–300 K. The samples were interrogated with a combination of optical absorption, hole burning, fluorescence excitation, steady state and picosecond time resolved fluorescence spectroscopy. Fair additivity of the LH1 and RC absorption spectra suggests rather weak electronic coupling between them. A low-energy tail revealed at cryogenic temperatures in the absorption spectra of both monomeric and dimeric... (More)

In the present work, spectral and kinetic changes accompanying the assembly of the light-harvesting 1 (LH1) complex with the reaction center (RC) complex into monomeric RC-LH1 and dimeric RC-LH1-PufX core complexes of the photosynthetic purple bacterium Rhodobacter sphaeroides are systematically studied over the temperature range of 4.5–300 K. The samples were interrogated with a combination of optical absorption, hole burning, fluorescence excitation, steady state and picosecond time resolved fluorescence spectroscopy. Fair additivity of the LH1 and RC absorption spectra suggests rather weak electronic coupling between them. A low-energy tail revealed at cryogenic temperatures in the absorption spectra of both monomeric and dimeric core complexes is proved to be due to the special pair of the RC. At selected excitation intensity and temperature, the fluorescence decay time of core complexes is shown to be a function of multiple factors, most importantly of the presence/absence of RCs, the supramolecular architecture (monomeric or dimeric) of the complexes, and whether the complexes were studied in a native membrane environment or in a detergent - purified state.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
keywords
Excitation energy transfer, Exciton, Light-harvesting, Photosynthesis, Spectroscopy
in
Biochimica et Biophysica Acta - Bioenergetics
volume
1857
issue
11
pages
7 pages
publisher
Elsevier
external identifiers
  • pmid:27514285
  • scopus:84982112109
ISSN
0005-2728
DOI
10.1016/j.bbabio.2016.08.001
language
English
LU publication?
no
additional info
Publisher Copyright: © 2016 Elsevier B.V.
id
e7c89ed8-c1f8-48c0-86df-e3a7eea283ff
date added to LUP
2023-06-16 10:41:36
date last changed
2024-01-05 02:39:58
@article{e7c89ed8-c1f8-48c0-86df-e3a7eea283ff,
  abstract     = {{<p>In the present work, spectral and kinetic changes accompanying the assembly of the light-harvesting 1 (LH1) complex with the reaction center (RC) complex into monomeric RC-LH1 and dimeric RC-LH1-PufX core complexes of the photosynthetic purple bacterium Rhodobacter sphaeroides are systematically studied over the temperature range of 4.5–300 K. The samples were interrogated with a combination of optical absorption, hole burning, fluorescence excitation, steady state and picosecond time resolved fluorescence spectroscopy. Fair additivity of the LH1 and RC absorption spectra suggests rather weak electronic coupling between them. A low-energy tail revealed at cryogenic temperatures in the absorption spectra of both monomeric and dimeric core complexes is proved to be due to the special pair of the RC. At selected excitation intensity and temperature, the fluorescence decay time of core complexes is shown to be a function of multiple factors, most importantly of the presence/absence of RCs, the supramolecular architecture (monomeric or dimeric) of the complexes, and whether the complexes were studied in a native membrane environment or in a detergent - purified state.</p>}},
  author       = {{Freiberg, Arvi and Chenchiliyan, Manoop and Rätsep, Margus and Timpmann, Kõu}},
  issn         = {{0005-2728}},
  keywords     = {{Excitation energy transfer; Exciton; Light-harvesting; Photosynthesis; Spectroscopy}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{11}},
  pages        = {{1727--1733}},
  publisher    = {{Elsevier}},
  series       = {{Biochimica et Biophysica Acta - Bioenergetics}},
  title        = {{Spectral and kinetic effects accompanying the assembly of core complexes of Rhodobacter sphaeroides}},
  url          = {{http://dx.doi.org/10.1016/j.bbabio.2016.08.001}},
  doi          = {{10.1016/j.bbabio.2016.08.001}},
  volume       = {{1857}},
  year         = {{2016}},
}