Thermal Casimir effect in lipid bilayer tubules.
We calculate the thermal Casimir effect for a dielectric tube of radius R and thickness delta formed from a membrane in water. The method uses a field-theoretic approach in the grand canonical ensemble. The leading contribution to the Casimir free energy behaves as -k(B)TLkappa(c)/R giving rise to an attractive force which tends to contract the tube. We find that kappa(c) approximately 0.3 for the case of typical lipid membrane t tubules. We conclude that except in the case of a very soft membrane this force is insufficient to stabilize such tubes against the bending stress which tends to increase the radius.
Dean
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DS
DAMTP, CMS, University of Cambridge, Cambridge, CB3 0WA, United Kingdom.
Horgan
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RR
D003198:Computer Simulation; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D008870:Microtubules / Q000737:chemistry*; D008954:Models, Biological; D008956:Models, Chemical; D013314:Stress, Mechanical; D013696:Temperature; D014867:Water / Q000737:chemistry*
D008051:Lipid Bilayers; D014867:Water