Research group Joachim Seelig

The biophysics of the biological membrane

Specially developed biophysical methods allow various insights into the structure of the cell membrane, the interactions between the membrane components, and the transport of molecules through the membrane.

Membranes, micelles, and detergents.

Each cell is an independent entity, separated from neighboring cells by a thin membrane, the biomembrane. The biological membrane is only a millionth of a centimeter thick and is composed of lipids and proteins. So far, some 10,000 lipids have been identified chemically. The cell membrane of a red blood cell alone contains about 400 different lipids. Why nature synthesizes such a large number of different lipids has still not been explained.

Atomic insight into the lipid membrane

We have developed physical methods to quantitatively determine the structure of the liquid-crystalline lipid membrane with atomic resolution: our results have become the international gold standard for the dynamic molecular description of lipid membranes. The structure of the interface between the lipid membrane and the internal or external aqueous phase is a particular challenge. We have been able to show that the head groups of lipids at this interface react like electrical voltmeters.

Biophysical methods for investigating biomembranes

Biomembranes are highly organized structures. Special methods, such as deuterium and phosphorus nuclear magnetic resonance, spin labeling, EPR spectroscopy, titration calorimetry and monolayer procedures, have had to be developed to quantitatively determine the interactions between proteins and lipids.

Transport of peptides through the membrane

Biological macromolecules are being used increasingly often in the treatment of disease. The transport of these biologics through the biomembrane requires special transport pathways. Using small peptide molecules, we are able to decode the various transport processes and determine them quantitatively.