title: Stark fluorescence spectroscopy reveals two emitting sites in the dissipative state of FCP antennas.
abstract: Diatoms are characterized by very efficient photoprotective mechanisms where the excess energy is dissipated as heat in the main antenna system constituted by fucoxanthin-chlorophyll (Chl) protein complexes (FCPs). We performed Stark fluorescence spectroscopy on FCPs in their light-harvesting and energy dissipating states. Our results show that two distinct emitting bands are created upon induction of energy dissipation in FCPa and possibly in FCPb. More specifically one band is characterized by broad red shifted emission above 700nm and bears strong similarity with a red shifted band that we detected in the dissipative state of the major light-harvesting complex II (LHCII) of plants [26]. We discuss the results in the light of different mechanisms proposed to be responsible for photosynthetic photoprotection.
authors.affiliation: Division of Physics and Astronomy, Department of Biophysics, VU University Amsterdam, The Netherlands; Department of Physics, University of Dhaka, Dhaka 1000, Bangladesh. Electronic address: m.d.wahadoszamen@vu.nl.
authors.forename: Md
authors.initials: M
authors.lastname: Wahadoszamen
authors.forename: Artur
authors.initials: A
authors.lastname: Ghazaryan
authors.forename: Hande E
authors.initials: HE
authors.lastname: Cingil
authors.forename: Anjue Mane
authors.initials: AM
authors.lastname: Ara
authors.forename: Claudia
authors.initials: C
authors.lastname: Büchel
authors.forename: Rienk
authors.initials: R
authors.lastname: van Grondelle
authors.forename: Rudi
authors.initials: R
authors.lastname: Berera
mesh_terms: D061146:Chlorophyll Binding Proteins / Q000737:chemistry*; D017377:Diatoms / Q000737:chemistry* / Q000502:physiology; D004734:Energy Metabolism; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry*; D010788:Photosynthesis; D013050:Spectrometry, Fluorescence; D024341:Xanthophylls / Q000737:chemistry*
chemical_list: D061146:Chlorophyll Binding Proteins; D045342:Light-Harvesting Protein Complexes; D024341:Xanthophylls; C025164:fucoxanthin
keywords: Charge transfer states; Diatoms; Energy dissipation; Light harvesting antenna; Nonphotochemical quenching; Stark spectroscopy