Asymmetric Membranes

All plasma membranes - the outer "envelope" of every cell - are asymmetric. This means that the lipids on the inside and outside of the membrane are chemically different. Cells invest a great deal of energy in building and maintaining this asymmetry. Why they do this is the subject of intense research. Diseased cells often have an altered lipid pattern or, like cancer cells, lose their asymmetry. We may even be able to reverse pathological processes by targeting membrane asymmetry.

How asymmetric membranes work

We want to find out how one side of the membrane affects the other and how membrane proteins respond. This will give us a better understanding of how signals are transmitted across the plasma membrane.

Our research shows that lipids can influence the opposite side of the membrane in different ways - for example, by making it tighter or looser. In addition, asymmetric membranes often have a much higher bending strength than symmetric ones. By measuring the function of proteins in such membranes, we can directly relate changes to these particular membrane properties.

Publications:

Schema eines Proteins in einer asymmetrischen Membran
Schematische Darstellung Wirkung einer lateralen Druckverteilung in einer asymmetrischen Membran auf Dimere des Outer Membrane Phospholipiase (OmpLA) Proteins.
Design: P. Piller

Examples

Schema der Lipidkopplung in asymmetrischen Membranen ©Moritz Frewein
©Moritz Frewein
Different scenarios of the coupling of asymmetric membranes
From: Frewein et al, JMB (2022), License: (CC-BY 4.0 DEED).
Proteinaktivitätsmessungen
The membrane enzyme OmpLA works at different rates in symmetric and asymmetric membranes.
From: Pabst & Keller, TIBS (2024), License: (CC-BY 4.0 DEED).
Schema von FRET Messungen ©M. Kaltenegger (U. Graz)
©M. Kaltenegger (U. Graz)
Schematic representation of the measurement of protein-protein interactions.
Design: M. Kaltenegger