Scattering Signatures of Complex Lipid Membranes: Spherical Vesicles vs. Planar Patches

Abstract

The spatial organization of cellular membranes plays a crucial role for a large number of biological processes. Multicomponent lipid bilayers are a useful model system to study to what extent lipids and sterols can drive this organization. Multiple theoretical and experimental studies have investigated the scattering signatures of composition heterogeneities in complex lipid systems. While the former typically consider a flat and periodically replicated membrane system, neutron scattering experiments can be performed on unilamellar vesicles. This work addresses the question how and to what extent the scattering signatures of these two geometrically different systems are related to one another. We consider a generic model for a homogeneous two-dimensional material for which we compute the structure function in both planar and spherical geometries, and we derive analytical relationships between these quantities. These results enable the direct, albeit approximate, comparison between theoretical/computational and experimental scattering data.