FTIR Detection of Water-sensitive Low-frequency Vibrational Modes during Photosynthetic Water Oxidation in Photosystem II

DOI

Bibliographic Information

Other Title
  • 低波数赤外分光法による光合成酸素発生反応中間体の検出：水の同位体置換の効果

Abstract

Photosynthetic water oxidation is catalyzed by the tetranuclear Mn-cluster of photosystem (PS) II. Two water molecules are oxidized to an oxygen molecule through five intermediates states (S0-S4). In the present study, flash-induced low-frequency (1000-370 cm-1) FTIR difference spectra for the S-state cycle and effects of H218O-, D216O-, D218O-substitution on the spectra were examined using PS II core particles from Thermosynechococcus elongatus. Low-frequency difference spectra for S1-to-S2, S2-to-S3, S3-to-S0, and S0-to-S1 transitions showed characteristic vibrational features depending on each water-substitution. Close inspection of the isotopic bands revealed that bands only sensitive to 16O/18O exchange or H/D exchange may be ascribed to mainly Mn cluster core vibrations or modes from amino acid side chains and polypeptides. Furthermore, bands sensitive to both 16O/18O and H/D exchanges may be attributed to the interaction between Mn and substrate water and/or water-derived chemical species involved in the water oxidation chemistry.

Journal

Details 詳細情報について

  • CRID
    1390001205626853504
  • NII Article ID
    130006986959
  • DOI
    10.14841/jspp.2005.0.010.0
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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