Functioning of oligomeric-type light-harvesting antenna.
In our previous work, we developed, for the first time, a theory of excitation energy transfer within an oligomeric-type light-harvesting antenna and, in particular, within the chlorosome of green bacteria (Biophys.J., 1996, vol.71, pp.995-1010). The theory was recently developed for a new original exciton model of aggregation of chlorosomal pigments, bacteriochlorophylls (BCh1) c/d/e (Biochem, Mol.Biol.Int., 1996, vol.40, No.2, pp. 243-252). In this paper, it was demonstrated with picosecond fluorescence spectroscopy that this theory explains the antenna-size-dependent kinetics of fluorescence decay in chlorosomal antenna, measured for intact cells of different cultures of the green bacterium Chlorobium limicola with different chlorosomal antenna size determined by electron microscopic examination of the ultrathin sections of the cells. According to our model, the energy transfer dynamics within the chlorosome imply the formation of a cylindrical exciton, delocalized over a tubular aggregate of BCh1 c chains, and inductive-resonance-type transfer of such a cylindrical exciton between the nearest tubular BCh1 c aggregates and to BCh1 a of the chlorosome.
Timpmann
K E
KE
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
Taisova
A S
AS
Novoderezhkin
V I
VI
Fetisova
Z G
ZG
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000737:chemistry* / Q000378:metabolism*; D019414:Chlorobi / Q000648:ultrastructure*; D004735:Energy Transfer; D007700:Kinetics; D008027:Light; D046911:Macromolecular Substances; D013050:Spectrometry, Fluorescence
D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; D046911:Macromolecular Substances; C002084:bacteriochlorophyll c