Berlin 2012 – scientific programme
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BP: Fachverband Biologische Physik
BP 26: Posters: Membranes and Vesicles
BP 26.8: Poster
Thursday, March 29, 2012, 17:30–19:30, Poster A
Membrane Undulations in Ion Channel Systems Undergoing Stochastic Resonance — •Eric Stava1, Siyoung Choi2, Minrui Yu2, Hyuncheol Shin2, and Robert Blick1,2 — 1Universität Hamburg, Hamburg, Deutschland — 2University of Wisconsin-Madison, Madison, Wisconsin, USA
Stochastic resonance (SR) is the process by which the signal-to-noise ratio of a system is enhanced by an increase in noise. It has been shown that Alamethicin ion channels undergo SR when appropriate levels of voltage noise are applied to them [1,2]. However, changes in the tension of the lipid membrane must also be taken into account. The converse flexoelectric effect enhances the tension in the lipid membrane in the presence of an applied voltage [3]. When voltage noise is applied to the system, this effect causes the lipid membrane to undulate. These membrane undulations enhance the time-averaged membrane area and system capacitance. From the real-time admittance of Alamethicin ion channels undergoing SR, we quantified the effects of voltage noise on the lipid membrane. We find a frequency-dependent enhancement in the system admittance with increasing voltage noise. This increase in admittance correlates with an increase in membrane tension, which enhances the time-averaged ion channel conductance. This results in improved signal transduction over a range of noise intensities.
[1] S. M. Bezrukov and I. Vodyanoy, Nature, 378, 362-364 (1995). [2] E. Stava, et al., submitted for publication. [3] A. T. Todorov, A. G. Petrov, and J. H. Fendler, J. Phys. Chem., 98, 3076-3079 (1994