Evidence for uncorrelated tilted layer structure and electrically polarized bilayers in amphiphilic glycolipids

Abstract

A strong low-frequency dielectric relaxation mode spanning from below 100 Hz at low temperatures to 100 kHz at high temperature, x-ray diffraction studies, and optical microscopic observations show, contrary to the currently accepted models, that the glycolipid molecules are tilted with respect to the layer normal in the smectic phase but the tilt direction is not correlated between the bilayers. The tilted glycolipid bilayers are electrically polarized. The tilted structure and the electric polarization of amphiphilic glycolipids may play an important role in biological cell membrane.