Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 26: INTERNAL SYMPOSIUM Optical Spectroscopy I
CPP 26.3: Vortrag
Donnerstag, 29. März 2007, 11:00–11:15, H40
The Interplay between Symmetry and Electronic Structure of Pigment-Protein Complexes from Purple Bacteria — •Silke Oellerich1, Martin Richter1, Jürgen Baier1, Thomas Prem1, Francesco Francia2, Giovanni Venturoli2, Dieter Oesterhelt3, June Southall4, Richard Cogdell4, and Jürgen Köhler1 — 1Experimentalphysik IV, Universität Bayreuth — 2University of Bologna — 3MPI für Biochemie, Martinsried — 4University of Glasgow
A recent rather low resolution X-ray crystal structure of the RC-LH1 core complex from the photosynthetic purple bacterium Rps. palustris showed the presence of a physical gap in the LH1 ring. The presence of such a gap, though functionally critical for the cyclic electron transport in the photosynthetic process, has become very controversial. We have now applied single-molecule spectroscopy to the RC-LH1 complexes of the purple bacteria Rps. palustris and Rb. sphaeroides (pufX- strain) to demonstrate that there is such a gap in the LH1 ring structure.
More then 80% of the complexes from Rb. sphaeroides only show broad absorption bands, whereas all of the measurable complexes from Rps. palustris also have a narrow line at the low-energy end of their spectrum. We describe how the presence of this narrow feature indicates the presence of a gap in the electronic structure of the LH1 from Rps. palustris, which provides strong support for the physical gap that was previously modelled in its X-ray crystal structure.