Energy transfer in reconstituted peridinin-chlorophyll-protein complexes: ensemble and single-molecule spectroscopy studies.
We combine ensemble and single-molecule spectroscopy to gain insight into the energy transfer between chlorophylls (Chls) in peridinin-chlorophyll-protein (PCP) complexes reconstituted with Chl a, Chl b, as well as both Chl a and Chl b. The main focus is the heterochlorophyllous system (Chl a/b-N-PCP), and reference information essential to interpret experimental observations is obtained from homochlorophyllous complexes. Energy transfer between Chls in Chl a/b-N-PCP takes place from Chl b to Chl a and also from Chl a to Chl b with comparable Förster energy transfer rates of 0.0324 and 0.0215 ps(-1), respectively. Monte Carlo simulations yield the ratio of 39:61 for the excitation distribution between Chl a and Chl b, which is larger than the equilibrium distribution of 34:66. An average Chl a/Chl b fluorescence intensity ratio of 66:34 is measured, however, for single Chl a/b-N-PCP complexes excited into the peridinin (Per) absorption. This difference is attributed to almost three times more efficient energy transfer from Per to Chl a than to Chl b. The results indicate also that due to bilateral energy transfer, the Chl system equilibrates only partially during the excited state lifetimes.
Mackowski
Sebastian
S
Department of Chemistry and Biochemistry and Center for Nanoscience, Ludwig Maximilian University, D-81377 Munich, Germany.
Wörmke
Stephan
S
Brotosudarmo
Tatas H P
TH
Jung
Christophe
C
Hiller
Roger G
RG
Scheer
Hugo
H
Bräuchle
Christoph
C
D000818:Animals; D002338:Carotenoids / Q000737:chemistry* / Q000378:metabolism; D002734:Chlorophyll / Q000737:chemistry* / Q000378:metabolism; D004141:Dinoflagellida; D004735:Energy Transfer / Q000502:physiology*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000502:physiology; D013050:Spectrometry, Fluorescence; D018724:Spinacia oleracea
D045322:Photosynthetic Reaction Center Complex Proteins; D002734:Chlorophyll; C016040:peridinin; D002338:Carotenoids