Thermodynamic analysis of VEGF-A165 binding to VEGFR-2 D23 and the full-length ECD. (A-B) Raw titration data of VEGFR-2 domains 2 and 3 and full-length ECD with VEGF-A165, respectively. (C) Integrated and concentration normalized isothermograms from panels A and B. Solid lines represent the best fit according to the “One Set of Sites” model. (D) Thermodynamic analysis of the interaction of VEGFR-2 with VEGF. All reactions are driven by entropy and inhibited by enthalpy. The stoichiometry and binding constants are displayed in the corresponding parts of the panel. R-2 indicates VEGFR-2.