Berlin 2005 – wissenschaftliches Programm
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MO: Molekülphysik
MO 12: Biomolecules I
MO 12.7: Vortrag
Freitag, 4. März 2005, 15:45–16:00, HU 2091
THz-Biology: Studying protein dynamics in solution — •Udo Heugen1, Erik Bründermann1, Matthias Krüger1, David Leitner2, Seung Joon Kim3, Martin Grübele3 und Martina Havenith1 — 1Dept. of Physical Chemistry II, Ruhr-Universität, Bochum, Germany — 2Dept. of Chemistry, University of Nevada, Reno, USA — 3Dept. of Chemistry and Physics, University of Illinois, Urbana, USA
We have developed a THz spectrometer to measure absorption spectra of solvated proteins. The radiation source is a p-type germanium laser which delivers output powers of several watts in the THz regime (from 1-4 THz). This allows us to penetrate relatively thick water layers (up to 0.3 mm) yielding reliable absorption in this experimentally difficult to access region. Using this setup we have investigated the changes in the water network by adding a solute in water and have started to systematically investigate the relation of tertiary and secondary structural changes to its spectrum. We will present the results for different mutants of ubiquitin and Lambda-repressor which serve as prototype systems and compare them with theoretical studies using molecular dynamics simulation. Our goal is to explore the large amplitude motions of proteins, which are assumed to be important for signal transfer and will foster folding. THz spectroscopy might open a new experimental window of fast protein dynamics in the future. We want to discuss the experimental setup and show first results that these methods allow direct experimental access to the change in the water network around the solute.