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Energy dissipation mechanisms in the FCPb light-harvesting complex of the diatom Cyclotella meneghiniana

dc.contributor.authorElnour, Huzifa Mohammed Ahamed Mohammed
dc.contributor.authorDietzel, Lars
dc.contributor.authorRamanan, Charusheela
dc.contributor.authorBüchel, Claudia
dc.contributor.authorVan Grondelle, Rienk
dc.contributor.authorKruger, T.P.J. (Tjaart)
dc.contributor.emailtjaart.kruger@up.ac.zaen_ZA
dc.date.accessioned2019-03-26T14:08:32Z
dc.date.issued2018-10
dc.description.abstractTransient absorption spectroscopy has been applied to investigate the energy dissipation mechanisms in the nonameric fucoxanthin-chlorophyll-a,c-binding protein FCPb of the centric diatom Cyclotella meneghiniana. FCPb complexes in their unquenched state were compared with those in two types of quenching environments, namely aggregation-induced quenching by detergent removal, and clustering via incorporation into liposomes. Applying global and target analysis, in combination with a fluorescence lifetime study and annihilation calculations, we were able to resolve two quenching channels in FCPb that involve chlorophyll-a pigments for FCPb exposed to both quenching environments. The fast quenching channel operates on a timescale of tens of picoseconds and exhibits similar spectral signatures as the unquenched state. The slower quenching channel operates on a timescale of tens to hundreds of picoseconds, depending on the degree of quenching, and is characterized by enhanced population of low-energy states between 680 and 710 nm. The results indicate that FCPb is, in principle, able to function as a dissipater of excess energy and can do this in vitro even more efficiently than the homologous FCPa complex, the sole complex involved in fast photoprotection in these organisms. This indicates that when a complex displays photoprotection-related spectral signatures in vitro it does not imply that the complex participates in photoprotection in vivo. We suggest that FCPa is favored over FCPb as the sole energy-regulating complex in diatoms because its composition can more easily establish the balance between light-harvesting and quenching required for efficient photoprotection.en_ZA
dc.description.departmentPhysicsen_ZA
dc.description.embargo2019-10-01
dc.description.librarianhj2019en_ZA
dc.description.sponsorshipThe National Research Foundation (NRF) of South Africa through grants no. 88653 and 106298 (H.M.A.M.E.) and grant no. N00500 (T.P.J.K.), the South Africa – VU University – Strategic Alliances (SAVUSA) Skill Programme (H.M.A.M.E.), the South African Institute of Physics Biophysics Initiative (H.M.A.M.E.); the Energy Institutional Research Theme and Research Development Programme of the University of Pretoria (T.P.J.K.), the Feodor-Lynen Fellowship of the Alexander von Humboldt Foundation (L.D.), Kerstin Pieper for experimental help in FCPb preparation (L.D), the Deutsche Forschungsgemeinschaft (DFG) (Grant Bu 812/10-1) (C.B.), an Advanced Investigator Grant (267333, PHOTPROT) from the European Research Council (ERC) (R.v.G. and C.R.), and a grant from the Royal Netherlands Academy of Arts and Sciences (KNAW) (R.v.G.).en_ZA
dc.description.urihttp://www.elsevier.com/locate/bbabioen_ZA
dc.identifier.citationElnour, H.M.A.M., Dietzel, L., Ramanan, C. et al. 2018, 'Energy dissipation mechanisms in the FCPb light-harvesting complex of the diatom Cyclotella meneghiniana', Biochimica et Biophysica Acta (BBA) - Bioenergetics, vol. 1859, no. 10, pp. 1151-1160.en_ZA
dc.identifier.issn0005-2728
dc.identifier.other10.1016/j.bbabio.2018.07.009
dc.identifier.urihttp://hdl.handle.net/2263/68717
dc.language.isoenen_ZA
dc.publisherElsevieren_ZA
dc.rights© 2018 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Biochimica et Biophysica Acta - Bioenergetics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Biochimica et Biophysica Acta - Bioenergetics, vol. 1859, no. 10, pp. 1151-1160, 2018. doi : 10.1016/j.bbabio.2018.07.009.en_ZA
dc.subjectDiatomen_ZA
dc.subjectLight harvesting antennaen_ZA
dc.subjectProteoliposomeen_ZA
dc.subjectFucoxanthin-chlorophyll proteinen_ZA
dc.subjectNonphotochemical quenchingen_ZA
dc.subjectTransient absorption spectroscopyen_ZA
dc.subjectPicosecond fluorescenceen_ZA
dc.subjectChloroplast membranesen_ZA
dc.subjectPhotosystem IIen_ZA
dc.subjectLHCIIen_ZA
dc.subjectDiadinoxanthinen_ZA
dc.subjectPlantsen_ZA
dc.subjectSpectroscopyen_ZA
dc.subjectCarotenoidsen_ZA
dc.subjectAggregationen_ZA
dc.titleEnergy dissipation mechanisms in the FCPb light-harvesting complex of the diatom Cyclotella meneghinianaen_ZA
dc.typePostprint Articleen_ZA

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