Ultrafast excitation dynamics of low energy pigments in reconstituted peripheral light‐harvesting complexes of photosystem I

FEBS Letters

Blankenship, Robert E.¹  Schmid, Volkmar H.R.³  Melkozernov, Alexander N.¹  Paulsen, Harald³  Schmidt, Gregory W.²  Lin, Su¹ 

[1] Department of Chemistry and Biochemistry and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, AZ 85287-1604, USA;Department of Botany, University of Georgia, Athens, GA 30602-7271, USA;Institut für Allgemeine Botanik, Johannes Gutenberg Universität, 55099 Mainz, Germany

关键词: Antenna;    Excitation energy transfer;    Light-harvesting complex;    LHCI-730 heterodimer;    Time-resolved spectroscopy;    Photosystem I;   

DOI  :  10.1016/S0014-5793(00)01370-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ultrafast dynamics of a reconstituted Lhca4 subunit from the peripheral LHCI-730 antenna of photosystem I of higher plants were probed by femtosecond absorption spectroscopy at 77 K. Intramonomeric energy transfer from chlorophyll (Chl) b to Chl a and energy equilibration between Chl a molecules observed on the subpicosecond time scale are largely similar to subpicosecond energy equilibration processes within LHCII monomers. However, a 5 ps equilibration process in Lhca4 involves unique low energy Chls in LHCI absorbing at 705 nm. These pigments localize the excitation both in the Lhca4 subunit and in LHCI-730 heterodimers. An additional 30–50 ps equilibration process involving red pigments of Lhca4 in the heterodimer, observed by transient absorption and picosecond fluorescence spectroscopy, was ascribed to intersubunit energy transfer.

【 授权许可】

Unknown