Fluorescence spectroscopy of reconstituted peridinin-chlorophyll-protein complexes.
Peridinin-chlorophyll-proteins (PCP) were reconstituted with binary 1:1 chlorophyll (Chl) mixtures of Chl a, Chl b, [3-acetyl]-Chl a (acChl a), and studied by bulk and single-molecule fluorescence spectroscopy. The latter provides a way to distinguish in a given sample hetero-chlorophyllous complexes that contain two different Chls from homo-chlorophyllous ones containing the same Chl in both binding sites. The results are compared with those of homo-chlorophyllous PCP reconstituted with pure Chl a, Chl b, or acChl a. Relative intensities of the Chl fluorescence in hetero-chlorophyllous complexes were obtained and modeled using the Förster description of energy transfer combined with known variations of peridinin (Per)-Chl excitation transfer rates for the different Chl pigments. In the case of hetero-chlorophyllous complexes containing acChl a, the energy transfer is unidirectional in the energetically preferable direction, while it is bi-directional in the sample reconstituted with Chl a and Chl b.
Mackowski
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Department of Chemistry and Biochemistry and Center for Nanoscience, Ludwig-Maximilian-University, Butenandtstrasse 11, 81377, Munich, Germany. sebastian.mackowski@cup.uni-muenchen.de
Wörmke
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Brotosudarmo
T H P
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Scheer
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Bräuchle
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D002338:Carotenoids / Q000737:chemistry*; D002734:Chlorophyll / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*
D002734:Chlorophyll; C016040:peridinin; D002338:Carotenoids