Eur. Phys. J. E (2005) 17: 203-208
https://doi.org/10.1140/epje/i2005-10008-8

Regular Articles

Contribution of the Nernst potential to stiffness constants: The asymmetrical case

IRPHE, UMR CNRS 6594, Universités Aix-Marseille I and II, Technopole de Chateau-Gombert, 13384, Marseille Cedex 13, France

^* e-mail: leonetti@irphe.univ-mrs.fr

Received: 25 January 2005
Accepted: 5 April 2005
Published online: 25 May 2005

Abstract

Inside biological membranes, one of the fundamental functions of active proteins such as pumps is to generate some electrochemical gradient across the membrane and then, to establish a new stationary state. The membrane electric potential generated by activity modifies the stiffness constants of the membrane. A spontaneous curvature appears if the inner and outer Debye lengths are different. The corresponding characteristic radius falls in the range from 0.08μm to 50μm. The bending elastic modulus is always increased. This effect is only noticeable in the limit of large Debye length from 0.5μm to 0.09μm. For a Nernst potential of 100mV and a Debye length of 0.2μ m, the bending modulus can reach 40k _B T.