Ultrafast excited state dynamics of spirilloxanthin in solution and bound to core antenna complexes: identification of the S∗ and T1 states.
Ultrafast excited state dynamics of spirilloxanthin in solution and bound to the light-harvesting core antenna complexes from Rhodospirillum rubrum S1 were investigated by means of femtosecond pump-probe spectroscopic measurements. The previously proposed S∗ state of spirilloxanthin was clearly observed both in solution and bound to the light-harvesting core antenna complexes, while the lowest triplet excited state appeared only with spirilloxanthin bound to the protein complexes. Ultrafast formation of triplet spirilloxanthin bound to the protein complexes was observed upon excitation of either spirilloxanthin or bacteriochlorophyll-a. The anomalous reaction of the ultrafast triplet formation is discussed in terms of ultrafast energy transfer between spirilloxanthin and bacteriochlorophyll-a.
The Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585 Japan. kosumi@sci.osaka-cu.ac.jp
Daisuke
D
Kosumi
Satoshi
S
Maruta
Tomoko
T
Horibe
Yuya
Y
Nagaoka
Ritsuko
R
Fujii
Mitsuru
M
Sugisaki
Richard J
RJ
Cogdell
Hideki
H
Hashimoto
D001426:Bacterial Proteins / Q000737:chemistry*; D004735:Energy Transfer; D007700:Kinetics; D010788:Photosynthesis; D012247:Rhodospirillum rubrum / Q000737:chemistry; D012996:Solutions / Q000737:chemistry*; D024341:Xanthophylls / Q000737:chemistry
D001426:Bacterial Proteins; D012996:Solutions; D024341:Xanthophylls; C026083:bacteriochlorophyll A proteins, Bacteria; C055255:spirilloxanthin