Role of Carotenoids in Light-Harvesting Processes in an Antenna Protein from the Chromophyte Xanthonema debile

0381460 - BC 2013 RIV US eng J - Článek v odborném periodiku
Durchan, Milan - Tichý, Josef - Litvín, Radek - Šlouf, V. - Gardian, Zdenko - Hříbek, P. - Vácha, František - Polívka, Tomáš
Role of Carotenoids in Light-Harvesting Processes in an Antenna Protein from the Chromophyte Xanthonema debile.
Journal of Physical Chemistry B. Roč. 116, č. 30 (2012), s. 8880-8889. ISSN 1520-6106. E-ISSN 1520-5207
Výzkumný záměr: CEZ:AV0Z50510513
Institucionální podpora: RVO:60077344
Klíčová slova: xanthophytes * carotenoids * light harvesting * energy transfer
Kód oboru RIV: BO - Biofyzika
Impakt faktor: 3.607, rok: 2012

We employed femtosecond transient absorption spectroscopy to study energy transfer pathways in the main light-harvesting complex of Xanthonema debile, denoted XLH, which contains four carotenoids, diadinoxanthin, heteroxanthin, diatoxanthin and vaucheriaxanthin, and Chl-a. Overall carotenoid-to-chlorophyll energy transfer efficiency is about 60%, but energy transfer pathways are excitation wavelength dependent. Energy transfer from the carotenoid S2 state is active after excitation at both 490 nm (maximum of carotenoid absorption) and 510 nm (red edge of carotenoid absorption), but this channel is significantly more efficient after 510 nm excitation. Concerning the energy transfer pathway from the S1 state, XLH contains two groups of carotenoids: those that have the S1 route active (~25%) and those having the S1 pathway silent. Besides the light-harvesting function, carotenoids in XLH also have photoprotective role; they quench Chl-a triplets via triplet-triplet energy transfer from Chl-a to carotenoid.
Trvalý link: http://hdl.handle.net/11104/0007164