Dresden 2011 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 26: Poster: Biomolecules
MO 26.4: Poster
Donnerstag, 17. März 2011, 16:00–18:00, P2
Fluorescence excitation spectroscopy of individual chlorosomes of Chlorobium Tepidum — •Marc Jendrny1, Thijs J. Aartsma2, and Jürgen Köhler1 — 1Experimental Physics IV, University of Bayreuth, 95448 Bayreuth, Germany — 2Department of Biophysics, University of Leiden, 9504 RA Leiden, The Netherlands
Chlorosomes are the main light-harvesting antennae complexes in green photosynthetic bacteria. These complexes feature a rod-like shape of 100 nm - 200 nm length and 20 nm - 50 nm width and consist of thousands of bacteriochlorophyll c, d or e depending on the species. The major difference from other light harvesting complexes is that the chromophores are not embedded into a protein-scaffold. It is assumed that these antenna complexes show a large variation with respect to size and that the mutual arrangement of the chromophores features a helical component giving rise to strong circular dichroism. We measured polarization-resolved fluorescence-excitation spectra from individual Chlorosomes of the green sulfur bacterium Chlorobium Tepidum this uncovers that the well known ensemble absorption band in the spectral range from 720 nm - 770 nm has contributions from at least two electronic transitions.