Regensburg 2007 – scientific programme

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BP: Fachverband Biologische Physik

BP 3: Membranes and Interfaces

BP 3.5: Talk

Monday, March 26, 2007, 15:15–15:30, H43

A novel method for measuring the bending rigidity of model lipid membranes by simulating tethers — •Vagelis Harmandaris and Markus Deserno — Max-Planck-Institute for Polymer Research*Max-Planck-Institute for Polymer Research, Theory Group, Mainz, Germany

The most common approach for measuring bending rigidities in simulations is from the spectrum of thermal shape fluctuations, which is the analogous of the experimental *flicker spectroscopy* technique. An alternative experimental method is to measure the tensile force needed to pull nanoscale bilayer tubes (tethers) from vesicles, since this force is proportional to the membrane's bending modulus and inversely proportional to the tube radius. Here, we show that this relation can be applied with even greater ease in computer simulations. Using a coarse-grained bilayer model developed recently [1], we efficiently obtain bending rigidities that compare very well with complementary measurements based on an analysis of thermal undulation modes. We furthermore illustrate that no deviations from simple quadratic continuum theory occur up to a radius of curvature comparable to the bilayer thickness [2].

References: 1. I.R. Cooke, K. Kremer and M. Deserno, Phys. Rev. E 72, 011506 (2005). 2. V. Harmandaris and M. Deserno, J. Chem. Phys. 125, 204905 (2006).