title: Excitation relaxation dynamics and energy transfer in pigment-protein complexes of a dinoflagellate, revealed by ultrafast fluorescence spectroscopy.
abstract: Photosynthetic light-harvesting complexes, found in aquatic photosynthetic organisms, contain a variety of carotenoids and chlorophylls. Most of the photosynthetic dinoflagellates possess two types of light-harvesting antenna complexes: peridinin (Peri)-chlorophyll (Chl) a/c-protein, as an intrinsic thylakoid membrane complex protein (iPCP), and water-soluble Peri-Chl a-protein, as an extrinsic membrane protein (sPCP) on the inner surface of the thylakoid. Peri is a unique carotenoid that has eight C=C bonds and one C=O bond, which results in a characteristic absorption band in the green wavelength region. In the present study, excitation relaxation dynamics of Peri in solution and excitation energy transfer processes of sPCP and the thylakoid membranes, prepared from the photosynthetic dinoflagellate, Symbiodinium sp., are investigated by ultrafast time-resolved fluorescence spectroscopy. We found that Peri-to-Chl a energy transfer occurs via the Peri S1state with a time constant of 1.5 ps or 400 fs in sPCP or iPCP, respectively, and that Chl c-to-Chl a energy transfer occurs in the time regions of 350-400 fs and 1.8-2.6 ps.
authors.affiliation: Graduate School of Science, Kobe University, Kobe, 657-8501, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Kobe University Research Center for Inland Seas, Awaji, 656-2401, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Iida
authors.affiliation: Department of Biology, Nippon Medical School, Musashino, 180-0023, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takaichi
authors.affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, 606-8501, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Mimuro
authors.affiliation: Graduate School of Science, Kobe University, Kobe, 657-8501, Japan.|Kobe University Research Center for Inland Seas, Awaji, 656-2401, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Murakami
authors.affiliation: Graduate School of Science, Kobe University, Kobe, 657-8501, Japan. akimoto@hawk.kobe-u.ac.jp.|Molecular Photoscience Research Center, Kobe University, Kobe, 657-8501, Japan. akimoto@hawk.kobe-u.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Akimoto
mesh_terms: D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D004141:Dinoflagellida / Q000378:metabolism*; D004735:Energy Transfer; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D020524:Thylakoids / Q000378:metabolism
chemical_list: D045342:Light-Harvesting Protein Complexes; D002734:Chlorophyll; C016040:peridinin; D002338:Carotenoids; D000077194:Chlorophyll A
keywords: Chlorophyll; Excitation energy transfer; Keto-carotenoid; Pigment–protein complex; Time-resolved fluorescence; Ultrafast spectroscopy