title: Energy equilibration and primary charge separation in chlorophyll d-based photosystem I reaction center isolated from Acaryochloris marina.
abstract: Primary photochemistry in photosystem I (PS I) reaction center complex from Acaryochloris marina that uses chlorophyll d instead of chlorophyll a has been studied with a femtosecond spectroscopy. Upon excitation at 630 nm, almost full excitation equilibration among antenna chlorophylls and 40% of the excitation quenching by the reaction center are completed with time constants of 0.6(+/-0.1) and 4.9(+/-0.6) ps, respectively. The rise and decay of the primary charge-separated state proceed with apparent time constants of 7.2(+/-0.9) and 50(+/-10) ps, suggesting the reduction of the primary electron acceptor chlorophyll (A(0)) and its reoxidation by phylloquinone (A(1)), respectively.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, Tatsunokuchi, Ishikawa 923-1292, Japan. kumazaki@jaist.ac.jp
authors.forename: Shigeichi
authors.initials: S
authors.lastname: Kumazaki
authors.forename: Kazuki
authors.initials: K
authors.lastname: Abiko
authors.forename: Isamu
authors.initials: I
authors.lastname: Ikegami
authors.forename: Masayo
authors.initials: M
authors.lastname: Iwaki
authors.forename: Shigeru
authors.initials: S
authors.lastname: Itoh
mesh_terms: D002734:Chlorophyll / Q000737:chemistry* / Q000302:isolation & purification; D000458:Cyanobacteria / Q000737:chemistry*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D002734:Chlorophyll; C107509:chlorophyll d