Biophysical Society Thematic Meeting | Ascona, Switzerland

Liposomes, Exosomes, and Virosomes: From Modeling Complex Membrane Processes to Medical Diagnostics and Drug Delivery

Tuesday Speaker Abstracts

Imagining Individual Receptors While Extracting Kinetic and Thermodynamic Parameters Using FD-based AFM David Alsteens , Université Catholique de Louvain, Louvain-La-Neuve, Belgium. Currently, there is a growing need for methods that can quantify and map the molecular interactions of biological samples, both with high-force sensitivity and high spatial resolution. Force-distance (FD) curve-based atomic force microscopy is a valuable tool to simultaneously contour the surface and map the biophysical properties of biological samples at the nanoscale. This presentation reports the use of advanced FD-based technology combined with chemically functionalized tips to probe the localization of specific sites on single native proteins and on living cells at high-resolution. Using biochemically sensitive tips, we are able to locate specific interaction sites on native protein at unprecedented resolution. We also introduce experimental and theoretical developments that allow force-distance curve-based atomic force microscopy (FD-based AFM) to simultaneously image native receptors in membranes and to quantify their dynamic binding strength to native and synthetic ligands. These binding strengths provide kinetic and thermodynamic parameters of individual ligand-receptor complexes. Signal Transduction on Membrane Surfaces: The Roles of Space, Force, and Time Jay T Groves . University of California, Berkeley, Berkeley, CA, USA. Most intracellular signal transduction reactions take place on the membrane surface. The membrane provides much more than just a surface environment on which signaling molecules are concentrated. There is a growing realization that multiple physical and chemical mechanisms allow the membrane to actively participate in the signaling reactions. Using a combination of single molecule imaging and spectroscopic techniques, my research seeks to directly resolve the actual mechanics of signaling reactions on membrane surfaces both in reconstituted systems and in living cells. These observations are revealing new insights into cellular signaling processes as well as some unexpected functional behaviors of proteins on the membrane surface.

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