Ultrafast Excitation Energy Dynamics in a Diatom Photosystem I-Antenna Complex: A Femtosecond Fluorescence Upconversion Study

Ryo Nagao, Kohei Kagatani, Yoshifumi Ueno, Jian Ren Shen, Seiji Akimoto

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

Fucoxanthin chlorophyll (Chl) a/c-binding proteins (FCPs) are unique light-harvesting antennas in diatoms. Recent time-resolved fluorescence analysis of photosystem I with FCP associated (PSI-FCPI) has mainly shown excitation energy transfer among Chls a from FCPI to PSI in tens of picoseconds. However, it remains unclear how each pigment, especially carotenoids and Chl c, in the FCPI is functionally related to the energy transfer in a femtosecond time range. Here, we reveal ultrafast excitation energy transfer mechanism in the PSI-FCPI preparations isolated from a diatom, Chaetoceros gracilis, by means of femtosecond time-resolved fluorescence spectroscopy with an upconversion system. Compared with the fluorescence lifetime components of PSI core-like complexes, the energy transfer of Chl c →Chl a in the FCPI was observed within hundreds of femtoseconds, and the energy in the FCPI was transferred to PSI in ∼2 ps. The comparative fluorescence analyses provide physical insights into the energy transfer machinery within FCPI and from FCPI to PSI.

Original languageEnglish
Pages (from-to)2673-2678
Number of pages6
JournalJournal of Physical Chemistry B
Volume123
Issue number12
DOIs
Publication statusPublished - Mar 28 2019

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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