Polarized fluorescence of aggregated bacteriochlorophyll c and baseplate bacteriochlorophyll a in single chlorosomes isolated from Chloroflexus aurantiacus

  • Shibata Y
  • Saga Y
  • Tamiaki H
 et al. 
  • 26


    Mendeley users who have this article in their library.
  • 26


    Citations of this article.


The polarization anisotropy of fluorescence from single chlorosomes isolated from a green filamentous bacterium, Chloroflexus aurantiacus, was measured using a confocal laser microscope at 13 K. Each single chlorosome that is floating in a frozen solvent exhibited strong polarization anisotropy of fluorescence. We calculated the degrees of fluorescence polarization for 51 floating single chlorosomes. The value ranged from 0.1 to 0.76 for the BChl-c aggregate in the core chlorosomes and from 0 to 0.4 for the energy acceptor BChl-a in the baseplate protein in the outer membrane. The shifts in polarization angles between the two emission bands were distributed over all the possible values with a sharp peak around 90 degrees , suggesting the perpendicular orientation between the transition dipoles of the fluorescence emission from the BChl-c aggregate and that from BChl-a. A simulation assuming a random orientation of chlorosomes reproduced the experimental results exactly. The analysis further indicated the appreciable contribution of the transition dipole of BChl-c that has an orientation perpendicular to the major polarization axis in each chlorosome. Small values of the degrees of polarization implied the BChl-a transition dipole to be somewhat tilted with respect to the normal of the cytoplasmic membrane to which chlorosomes are attached. These conclusions can be obtained only by observing the fluorescence of single chlorosomes.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Yutaka Shibata

  • Yoshitaka Saga

  • Hitoshi Tamiaki

  • Shigeru Itoh

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free