ELECTROSTATIC INTERACTIONS WITHIN HELICAL STRUCTURES OF CHIRAL LIPID BILAYERS

The electrostatic interaction from edge charges on an anisotropically bending ribbon is examined for its ability to stabilize helically wound structures. Helical forms can be stabilized by some charge configurations, but they are generally unstable toward closure into cylindrical tubules. The stable curvature of the ribbon is, however, inhibited by a potential energy barrier that develops in the presence of dilute concentrations of dissolved electrolytes in the medium around the ribbon. This model simulates the interactions of polarization charges present for a chiral lipid bilayer in a ferroelectric state. Application to solidus lipid bilayers in conventional aqueous solutions suggests a barrier height that will block tubule formation, thus discounting the significance of electrostatic interactions in the formation of helical and tubular structures of chiral bilayers.