Measuring binding of S100 proteins to RAGE by surface plasmon resonance.

Surface plasmon resonance (SPR) is a label-free biophysical method that allows to measure the binding parameters (ka, kd, K(D)) of the interaction between two molecules. In this method, one protein/molecule (ligand) is immobilized on the surface of a sensor chip, while the other molecule (analyte) is in solution. We describe here the use of SPR to measure the binding parameters of the interaction between S100 proteins and isolated domains of the receptor for advanced glycation endproducts (RAGE). In particular, we present the protocols that allow to measure the binding of S100B to RAGE V domain, and the binding of S100A1 and S100A6 to RAGE V-C1-C2 domain fused to a Glutathione S-Transferase (GST) moiety (GST-RAGE).