en
Scientific article
English

Optically detected magnetic resonance of intact membranes from Chloroflexus aurantiacus. Evidence for exciton interaction between the RC and the B808-866 complex

Published inPhotosynthesis research, vol. 71, no. 1/2, p. 45-57
Publication date2002
Abstract

Optically detected magnetic resonance of chlorosome-containing membranes from the green filamentous bacterium Chloroflexus aurantiacus has been performed both by fluorescence and absorption detection. Triplet states localized in the chlorosomes and in the B808–866 complex have been characterized. After chemical reduction with ascorbate followed by illumination at 200 K, recombination triplet state localized in the primary donor becomes largely populated under illumination at low temperature while all the antenna triplet states, which are localized in carotenoids and BChl a molecules, are strongly quenched. We were able to obtain the T-S spectrum of the primary donor P870 surrounded by all the antenna complexes connected to the RC via energy transfer and then in its intact environment. We found clear spectroscopic evidence for exciton interaction between the RC and the B808–866 antenna complex. This evidence was provided by the comparison of the T−S spectrum of P870 in the membranes with that of isolated RC. The analogy of some features of the difference spectra with those previously found in the same kind of experiments for Rb. sphaeroides, allows to predict a similar coupling among the primary donor and the nearby antenna BChl a molecules, assembled as circular aggregate.

eng
Keywords
  • ADMR
  • Bacteriochlorophy
  • B808-866
  • Carotenoid
  • Chlorosomes
  • FDMR
  • Reaction center
  • Triplet state
  • T-S
Affiliation Not a UNIGE publication
Citation (ISO format)
BORDIGNON, Enrica et al. Optically detected magnetic resonance of intact membranes from <i>Chloroflexus aurantiacus</i>. Evidence for exciton interaction between the RC and the B808-866 complex. In: Photosynthesis research, 2002, vol. 71, n° 1/2, p. 45–57. doi: 10.1023/A:1014947412940
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
ISSN of the journal0166-8595
17views
0downloads

Technical informations

Creation12/28/2023 9:57:59 AM
First validation01/03/2024 1:50:34 PM
Update time01/03/2024 1:50:34 PM
Status update01/03/2024 1:50:34 PM
Last indexation05/06/2024 5:41:04 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack