Complex Mimics of Biological Membranes

Biological membranes are highly complex composites of lipids, proteins and carbohydrates with various physiological functions that depend on the physicochemical properties of its constituents and their structural organization within the membranes on the nanoscopic to microscopic length scales. In the quest of understanding details of biomembrane function lipid-only mimics serve as valuable platforms for studying the functional role of membrane lipids under chemically and experimentally well-defined conditions. Of recent, we have particularly focused on complex mimics of mammalian and bacterial plasma membranes with either lateral or transbilayer inhomogeneities.

Applying small-angle X-ray/neutron scattering in combination with contrast variation and other complimentary techniques allowed us to gain detailed structural insight into either coexisting lipid domains, or transleaflet coupling mechanisms in asymmetric bilayers. Further, we are currently developing tools to obtain reliable values for intrinsic lipid curvatures, which play a pivotal role in coupling to protein function. I will present recent research highlights resulting from these efforts and discuss some applications to membrane-active drugs, such as antimicrobial peptides, or the partitioning of transmembrane proteins in raft-like lipid domains.