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CPP: Chemische Physik und Polymerphysik
CPP 3: Biomoleküle
CPP 3.5: Vortrag
Montag, 24. März 2003, 11:15–11:30, ZEU/118
Influence of Geometric Constraints on the Semiflexible Biopolymer Actin — •Sarah Köster1, Alexander Otten1, Myang Chul Choi2, Youli Li2, Cyrus R. Safinya2, and Thomas Pfohl1 — 1Angewandte Physik, Universität Ulm, Albert-Einstein-Allee 11, 89069 Ulm — 2Materials Research Laboratory, University of California, Santa Barbara, USA
Actin is one of the most important and most abundant proteins in eucariotic cells: it is part of the cytoskeleton and is responsible for transport mechanisms inside cells. On the other hand, filamentous actin serves as a good model system for semiflexible polymers. Thus mechanical properties of these biopolymers are of great interest for both physicists and biologists. Investigations of the influence of confined geometry on thermal fluctuations, diffusion, or self-organization of single biomacromolecules help to understand the molecular behavior of the polymers under confinement and the transport properties in networks. This knowledge is important for in vitro applications (microfluidics) as well as for a understanding of processes within the cell.
Single actin fibers can be brought into microchannels in filamentous form or polymerized from globular actin directly in the structures. The microchannel devices are fabricated by soft lithography. Using fluorescence video microscopy, thermal fluctuations of single actin polymers can be observed. Analyzing the fluctuations, we obtain information about the elongation of single biomacromolecules under alignment depending on the width and the geometry of the channels.