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CPP: Chemische Physik und Polymerphysik
CPP 17: Poster: Spectroscopy and Single Particle Spectroscopy of Molecular Systems, Photoprocesses, Biological Systems
CPP 17.24: Poster
Dienstag, 3. April 2001, 12:30–15:00, AT1
A first-principles study of 11-cis retinal: Modelling the chromophore-protein interaction in rhodopsin — •Sugihara Minoru1, Entel Peter1, and Buss Volker2 — 1Theoretical Physics, University of Duisburg, Germany — 2Theoretical Chemistry, University of Duisburg, Germany
The 11-cis-retinal protonated Schiff base is the
chromophore of rhodopsin, the photoreceptor in the eye.
The photochemical isomerization from 11-cis
to the all-trans form triggers a series of enzymatic reactions
known as the visual cascade which eventually leads to a neural signal.
Experiments such as resonance Raman, NMR etc., have shown that
11-cis-retinal is probably highly twisted in the protein
pocket. Because detailed knowledge about the kind of interaction
with the protein is missing, a theoretical description
of the chromophore conformation is difficult. In the simulations the
results of which will be presented here, we assume that
the retinal chromophore, as a consequence of the steric fit into the
protein
binding pocket, undergoes a specific kind of conformational change.
The structure we obtain is in good agreement with the experimentally
observed highly twisted conformation of the chromophore backbone.
V. Buss, O. Weingart, and M. Sugihara, Angew. Chem. Int.
Ed. 39 (2000) 2784.