TY - JOUR
T1 - Exciton interactions in the light-harvesting antenna of photosynthetic bacteria studied with triplet-singlet spectroscopy and singlet-triplet annihilation on the B820 subunit form of Rhodospirillum rubrum
AU - van Mourik, Frank
AU - van der Oord, Cornelis J.R.
AU - Visscher, Kees J.
AU - Parkes-Loach, Pamela S.
AU - Loach, Paul A.
AU - Visschers, Ronald W.
AU - van Grondelle, Rienk
N1 - Funding Information:
This work was supported by the Netherlands Organization for Pure Research via the Dutch Foundation for Biophysics and by EEC Grant No. SC1-0004-C. The technical assistance of Mr. W. Spierdijk is gratefully acknowledged.
PY - 1991/8/2
Y1 - 1991/8/2
N2 - The pigment-protein complex, B820, isolated from the long-wavelength antenna (LH-1) of the photosynthetic purple bacterium Rhodospirillum rubrum was studied with polarized nanosecond laser spectroscopy. The polarized triplet (T)-singlet (S) spectrum was obtained at 77 K. The spectrum is significantly different from the T-S spectrum of monomeric BChl a, and can be explained by assuming that upon excitation the absorption band at 825 nm, which is due to a dimeric pair of BChl a molecules, disappears from the absorption spectrum, and is replaced by a monomer absorption band peaking at 809 nm. From the energy-dependence of the triplet yield, the high polarization of the bleaching, and the absence of singlet-triplet quenching we conclude that the B820 complex contains only one dimer of interacting BChl a molecules.
AB - The pigment-protein complex, B820, isolated from the long-wavelength antenna (LH-1) of the photosynthetic purple bacterium Rhodospirillum rubrum was studied with polarized nanosecond laser spectroscopy. The polarized triplet (T)-singlet (S) spectrum was obtained at 77 K. The spectrum is significantly different from the T-S spectrum of monomeric BChl a, and can be explained by assuming that upon excitation the absorption band at 825 nm, which is due to a dimeric pair of BChl a molecules, disappears from the absorption spectrum, and is replaced by a monomer absorption band peaking at 809 nm. From the energy-dependence of the triplet yield, the high polarization of the bleaching, and the absence of singlet-triplet quenching we conclude that the B820 complex contains only one dimer of interacting BChl a molecules.
KW - Bacteriochlorophyll
KW - Exciton interaction
KW - Photosynthesis
UR - http://www.scopus.com/inward/record.url?scp=0025866044&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025866044&partnerID=8YFLogxK
U2 - 10.1016/S0005-2728(05)80193-8
DO - 10.1016/S0005-2728(05)80193-8
M3 - Article
AN - SCOPUS:0025866044
SN - 0005-2728
VL - 1059
SP - 111
EP - 119
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
IS - 1
ER -