The Physics of Non-Specific Interactions between Biomembranes

• Applicant: Professor Dr. Emanuel Schneck
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2014 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 256222543

Biomembranes are vital components of all living organisms. They form the boundaries between the various compartments of cells and act as platforms for essential biochemical processes. Membrane functions as well as their interactions with other membranes in the congested physiological surroundings are sensitive to the composition of the membrane surfaces, which are formed by the headgroups of lipids and by membrane-bound saccharides, polypeptides, and polymers. Over the first four years of the Emmy-Noether project we established methodology for the study of interacting membrane surfaces and comprehensively investigated the effects of membrane-bound polymers, saccharides, and other motifs on membrane interactions. However recent results have opened up important additional questions regarding the formation of highly ordered glycolipid domains, which have not been addressed so far. Our preliminary work indicates that the lateral arrangement of glycolipids in lipid membranes has a rich phenomenology, which is potentially of great biological relevance, for example for membrane trafficking and charge regulation. In the additional 12 months of funding, we will continue our efforts towards the investigation of glycolipid ordered domains in membranes composed of binary and ternary lipid mixtures. The formation of such domains is vastly unexplored, in particular when it comes to the domain internal structure on molecular length scales. To identify glycolipid domains and to structurally characterize them, we are going to exploit their headgroup-dependent structural fingerprint seen with surface-sensitive x-ray scattering techniques, as already demonstrated. The employed methodology was established only recently, so that the research can be considered very timely.

• DFG Programme: Independent Junior Research Groups