Carotenoid triplet states associated with the long-wavelength-emitting chlorophyll forms of photosystem I in isolated thylakoid membranes

J Phys Chem B. 2005 Jan 20;109(2):986-91. doi: 10.1021/jp047077k.

Abstract

The carotenoid triplet populations associated with the long-wavelength-emitting chlorophyll forms of photosystem I (PS I)(dagger) have been investigated in isolated spinach thylakoids by means of fluorescence-detected magnetic resonance in zero field. The spectra collected in the 730-800 nm emission range can be globally fitted assuming the presence of four different carotenoid triplet states coupled to long-wavelength-emitting forms of PS I, having zero-field-splitting parameters /D/ = 0.0359 cm(-1) and /E/ = 0.00371 cm(-1), /D/ = 0.0382 cm(-1) and /E/ = 0.00388 cm(-1), /D/ = 0.0395 cm(-1) and /E/ = 0.00397 cm(-1), and /D/ = 0.0405 cm(-1) and /E/ = 0.00411 cm(-1). On the basis of the triplet-associated fluorescence emission profile, it is suggested that those triplets are associated with light-harvesting complex I, the peripheral antenna complex of PS I.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carotenoids / chemistry*
  • Chlorophyll / chemistry*
  • Intracellular Membranes / chemistry*
  • Photosystem I Protein Complex / chemistry*
  • Sensitivity and Specificity
  • Spectrometry, Fluorescence / methods
  • Spinacia oleracea / chemistry
  • Thylakoids / chemistry*

Substances

  • Photosystem I Protein Complex
  • Chlorophyll
  • Carotenoids