Spectroscopy on individual light-harvesting 1 complexes of Rhodopseudomonas acidophila

Biophys J. 2002 Sep;83(3):1701-15. doi: 10.1016/S0006-3495(02)73938-6.

Abstract

In this paper the fluorescence-excitation spectra of individual LH1-RC complexes (Rhodopseudomonas acidophila) at 1.2 K are presented. All spectra show a limited number of broad bands with a characteristic polarization behavior, indicating that the excitations are delocalized over a large number of pigments. A significant variation in the number of bands, their bandwidths, and polarization behavior is observed. Only 30% of the spectra carry a clear signature of delocalized excited states of a circular structure of the pigments. The large spectral variety suggests that besides site heterogeneity also structural heterogeneity determines the optical spectrum of the individual LH1-RC complexes. Further research should reveal if such heterogeneity is a native property of the complex or induced during the experimental procedures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins*
  • Biophysical Phenomena
  • Biophysics
  • Light-Harvesting Protein Complexes*
  • Lipid Bilayers
  • Microscopy, Fluorescence
  • Models, Biological
  • Photosynthetic Reaction Center Complex Proteins / chemistry*
  • Photosynthetic Reaction Center Complex Proteins / ultrastructure
  • Protein Conformation
  • Rhodopseudomonas / metabolism*
  • Rhodopseudomonas / ultrastructure
  • Spectrometry, Fluorescence / methods

Substances

  • Bacterial Proteins
  • Light-Harvesting Protein Complexes
  • Lipid Bilayers
  • Photosynthetic Reaction Center Complex Proteins
  • light-harvesting complex 1, Rhodospirillum