Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
BP: Fachverband Biologische Physik
BP 5: Posters: Biopolymers and Biomaterials
BP 5.26: Poster
Montag, 22. März 2010, 17:15–20:00, Poster B1
Non-Gaussian tube width distributions in entangled solutions of filamentous actin — •Inka Lauter1, Masashi Degawa1, Norbert Kirchgeßner1, Bernd Hoffmann1, Rudolf Merkel1, Margret Giesen1, Jens Glaser2, Dipanjan Chakraborty2, and Klaus Kroy2 — 1Institute of Bio- and Nanosystems 4: Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich — 2Institute of Theoretical Physics, University of Leipzig, PF 100920, 04009 Leipzig, Germany
Actin is evolutionarily one of the most conserved components in eukaryotic cells. Actin filaments are interesting model systems to study the physical properties of semi-flexible polymers. One theoretical concept is the tube model which provides a simple phenomenological description of the complicated topological constraints in entangled solutions of semi-flexible polymers. Here, the tube defines the accessible space of a fluctuating filament which is topologically constrained by the presence of other filaments. Various theoretical models assume the tube width along the filament contour being constant. However, recent experiments and simulations showed substantial deviations from this assumption. We introduce a systematic extension [J. Glaser, I. Lauter et al., arXiv:0910.5864] of Morse's binary collision approximation (BCA) [D.C. Morse, PRE 63:031502 (2001)], which predicts a varying tube width along the filament contour. We measured tube width distributions of individual actin filaments as a function of filament density. Our experimental data are well described by the extended BCA model.