Berlin 2008 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 25: Protein Structure and Folding
BP 25.8: Vortrag
Donnerstag, 28. Februar 2008, 16:15–16:30, PC 203
Global Dynamics of Yeast Alcohol Dehydrogenase — •Biehl Ralf1, Hoffmann Bernd2, Fallus Peter3, Monkenbusch Michael1, Merkel Rudolf2, and Richter Dieter1 — 1Institut für Festkörperforschung, Forschungszentrum Jülich, Germany — 2Institut für Bio- und Nanosysteme, Forschungszentrum Jülich, Germany — 3Institut Laue-Langevin, Grenoble, France
The dynamics of proteins is a keystone to the understanding of their function as nanomachines or while metabolizing toxic by-products. To understand these processes we need information on length scales comparable to the size of the protein, which determine their functionality. Neutron spin echo spectroscopy is a versatile tool to determine the dynamics of macromolecules on these nanometer length and a nanosecond timescale. We will present NSE results from the protein Yeast Alcohol Dehydrogenase, which is a compact tetramer build up from 2 dimeric subunits involved in the production of ethanol. It binds the cofactor NAD in a cleft before catalysing the ethanol production. At low concentration around 1% the protein dynamics is observable with only small influence of protein-protein interactions at lowest q. The main characteristics of the protein dynamics can be described as the translational diffusion at low q and additional rotational diffusion at higher q, compatible with a rigid body model. We find additional dynamics at the onset of rotational diffusion, which is modelled in a first approach by a contribution due to elastic normal modes. The influence of the bound cofactor leads to a shift of the elastic contribution to higher q attributed to stronger coupling between the main domains.