Berlin 2008 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 36: Biopolymers and Biological Systems

CPP 36.8: Talk

Friday, February 29, 2008, 12:15–12:30, C 264

Protein dynamics-induced modulation of excitation energy transfer — •Marc Brecht, Volker Radics, Jana Berit Nieder, Hauke Studier, and Robert Bittl — Fachbereich Physik, Freie Universität Berlin, Arnimalle 14, 14195 Berlin, Germany

Electron and energy transfer in proteins are key processes in bioenergetics. Their understanding on a molecular level can serve as important guideline for the design of nanoscale assemblies. Energy transfer between pigment molecules requires a match between their transition energies for energy emission and absorption. The tuning of these pigment energies in proteins is achieved by pigment-protein interactions. In general, these interactions are regarded as static properties determined by the three-dimensional structure of pigment-protein complexes. Employing single-molecule fluorescence spectroscopy on photosystem I [1] we demonstrate that protein dynamics, even at cryogenic temperatures, significantly influences the transition energy of pigments and, as a consequence, modulates energy transfer pathways. Our finding shows that the energy transfer pathway in photosystem I is not uniquely defined by the three-dimensional structure of the complex. This variability of energy transfer pathways introduced by protein dynamics might be important for the extreme robustness of photosystems [2].

[1] Brecht, M., Studier, H., Elli, A. F., Jelezko, F., and Bittl, R. (2007) Biochemistry, 46(3):799-806. [2] Brecht M., Radics V., Nieder J. B., Studier H., Jelezko F., Bittl R. submitted