X-ray scattering from a thickness-modulated phase of lipid membranes

Abstract

An electron density model for small-angle X-ray scattering from a novel thickness-modulated phase of lipid membranes is presented, and analytical expressions are derived for the intensities of the diffraction peaks. Structural parameters of the membranes in this phase have been determined from a least-squares fit of the calculated intensities to the observed ones. The amplitude of the thickness modulation is found to be about an order of magnitude smaller than the membrane thickness, which accounts for the very small number and very weak intensities of the peaks arising from these modulations.