Beta-carotene to bacteriochlorophyll-c energy transfer in self-assembled aggregates mimicking chlorosomes

0348819 - BC 2012 RIV NL eng J - Journal Article
Alster, J. - Polívka, Tomáš - Arellano, J.B. - Chábera, P. - Vácha, František - Pšenčík, J.
Beta-carotene to bacteriochlorophyll-c energy transfer in self-assembled aggregates mimicking chlorosomes.
Chemical Physics. Roč. 373, 1-2 (2010), s. 90-97. ISSN 0301-0104. E-ISSN 1873-4421
R&D Projects: GA ČR GA206/09/0375
Institutional research plan: CEZ:AV0Z50510513
Keywords : carotenoids * chlorosomes * energy transfer
Subject RIV: BO - Biophysics
Impact factor: 2.017, year: 2010

Carotenoids are together with bacteriochlorophylls important constituents of chlorosomes, the light-harvesting antennae of green photosynthetic bacteria. Majority of bacteriochlorophyll molecules form self-assembling aggregates inside the chlorosomes. In this work, the ability of beta-carotene to induce aggregation of bacteriochlorophyll-c in aqueous buffer was studied. Excitation relaxation and energy transfer in the carotenoid-bacteriochlorophyll assemblies were measured using femtosecond and nanosecond transient absorption spectroscopy. A fast, similar to 100-fs energy transfer from the S2 state of beta-carotene to bacteriochlorophyll c was revealed, while no evidence for significant energy transfer from the S1 state was found. Picosecond formation of the carotenoid triplet state was observed, which was likely generated by singlet homo-fission from the S1 state of beta-carotene.
Permanent Link: http://hdl.handle.net/11104/0189241