Mapping and Quantifying individual interactions using FD-curves based AFM

Alsteens, David [UCL]

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.