Regensburg 2004 – wissenschaftliches Programm
CPP 13: SYMPOSIUM: Understanding and Controlling Complex Structures: From Synthetic Polymers to Biomaterials I
CPP 13.7: Vortrag
Dienstag, 9. März 2004, 11:45–12:00, H 37
Thermal Fluctuations of Individual Actin Filaments in Confined Geometry — •Sarah Köster1, Alexander Otten1, Stephan Herminghaus1,2 und Thomas Pfohl1 — 1Angewandte Physik, Universität Ulm, Albert-Einstein-Allee 11, 89081 Ulm — 2Max-Planck-Institut für Strömungsforschung, Bunsenstraße 10, 37073 Göttingen
The investigation of individual semiflexible biopolymers will bring new insights concerning microfluidic in vitro applications as well as the understanding of biomechanical processes within the cell. The chosen system, F-actin, is experimentally accessible quite well and it is one of the most important proteins in eucaryotic cells. Thermal fluctuations of individual fluorescently labeled actin filaments in confined geometry can directly be observed using microfluidic devices fabricated by soft lithography. Analyzing the fluorescence microscopy images of the contour line of the fluctuating biopolymers we have access to macromolecular characteristics such as the mean square end-to-end distance, the bending energy, and the tangent correlation function. While the tangent correlation function of free semiflexible polymers shows a simple exponential decay, a completely different behaviour can be observed when investigating individual actin polymers in confining microchannels. In this case the decay is superposed by an oscillation which allows for the determination of the deflection length λ in addition to the persistence length LP.