Carotenoids in Energy Transfer and Quenching Processes in Pcb and Pcb-PS I Complexes from Prochlorothrix hollandica

0345900 - BC 2012 RIV US eng J - Článek v odborném periodiku
Durchan, Milan - Herbstová, Miroslava - Fuciman, M. - Gardian, Zdenko - Vácha, František - Polívka, Tomáš
Carotenoids in Energy Transfer and Quenching Processes in Pcb and Pcb-PS I Complexes from Prochlorothrix hollandica.
Journal of Physical Chemistry B. Roč. 114, č. 28 (2010), s. 9275-9282. ISSN 1520-6106. E-ISSN 1520-5207
Grant CEP: GA AV ČR IAA608170604; GA AV ČR IAA608170603
Výzkumný záměr: CEZ:AV0Z50510513
Klíčová slova: carotenoids * oxyphotobacteria * energy transfer
Kód oboru RIV: BO - Biofyzika
Impakt faktor: 3.603, rok: 2010

Chlorophyll (Chl) a/b-binding proteins from Prochlorothrix hollandica known as Pcb antennae were studied by femtosecond transient absorption to identify energy transfer rates and pathways. Carotenoids transfer energy to Chl with low efficiency of ~25% in Pcb complexes. Analysis of transient absorption spectra identified a pathway from the hot S1 state of carotenoids as the major energy transfer channel between whereas the S2 state contributes only marginally to energy transfer. Due to energetic reasons, no energy transfer is possible via the relaxed S1 state of carotenoids. The low overall energy transfer efficiency of carotenoids recognizes chlorophylls as the main light-harvesting pigments. Besides Chl a, presence of Chl b, which transfers energy to Chl a with nearly 100% efficiency, significantly broadens the spectral range accessible for light-harvesting and improves cross-section of Pcb complexes. The major role of carotenoids in Pcb is photoprotection.
Trvalý link: http://hdl.handle.net/11104/0005962