Biophysics of membrane proteins with single-molecule resolution

Researchers: Johanna Gerstenecker, Alicia Damm, Ranjit Shiva Gulvady, Raju Regmi

Sub-project 1: Interplay of membrane curvature and transmembrane proteins

Transmembrane proteins are tightly embedded in fluid lipid bilayers where they diffuse laterally. Many membrane proteins are involved in the transport of ions or molecules through the membranes using different sources of energy (ATP hydrolysis, voltage, light, etc) that allow for conformational changes. How mechanical stresses on the membrane can affect these conformational changes and thus protein activity is still an open question. We investigate the feedback between the physical properties of membranes, the functional conformational dynamics of membrane proteins and their diffusion. We perform single molecule experiments on membrane proteins reconstituted in liposomes to study the effect of membrane curvature on the conformations of the protein.

Sub-project 2: DNA-FRET sensors to investigate protein clustering mechanisms

Membrane proteins play a crucial role in various biological phenomena such as endocytosis and signal transduction. These phenomena are heavily dependent on the clustering of membrane proteins. While the propensity of proteins to cluster on the cell membrane has been well established, the physical mechanisms that govern this behavior are far from clear. We combine elements from biophysics, cellular biology and biochemistry, to design a single-molecule FRET-based DNA nanosensor to measure the forces responsible for the clustering of membrane proteins.

Main collaborators

Daniel Levy (UMR 168)

Bassam Hajj (UMR 168)

Emmanuel Margeat (CBS, Montpellier)

Ludger Johannes (UMR3666/U1143)

John Ispen (Univ. Southern Denmark, Odense, Denmark)

Weria Pezeshkian (University of Groningen, Netherlands)