Dresden 2006 – scientific programme
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AKB: Biologische Physik
AKB 7: Biopolymers I
AKB 7.4: Talk
Tuesday, March 28, 2006, 10:45–11:00, ZEU 255
Entropic forces generated by grafted semiflexible polymers — •Azam Gholami1, Jan Wilhelm2, and Erwin Frey2 — 1Hahn-Meitner-Institut, Abteilung Theorie, Glienicker Str. 100, D-14109 Berlin, Germany — 2Arnold Sommerfeld Center for Theoritical Physics and CeNS, Department of Physics, Ludwig-Maximilian-Universität München, Theresienstrasse 37, D-80333 München, Germany
We compute both numerically and by Monte Carlo simulations the average force exerted by a fluctuating grafted semi-flexible polymer upon a rigid smooth wall as well as the corresponding free energy. Both quantities are thought to be of interest for understanding the physics of actin-polymerization driven cell motility and movement of bacteria like Listeria monocytogenes. Depending on the angle between the constraining wall and the direction of the graft, two asymptotic regimes with different dependence of the force on the position of the wall can be discerned. The angle determining the position of the crossover varies as the square root of the ratio of the polymer’s length to its persistence length. For angles larger than the critical angle, previous expressions are qualitatively valid but for smaller angles different behavior is found.