This work clearly demonstrates an evaluation process that is easily performed and is simply based on the fitting of temperature-dependent surface plasmon resonance (SPR) sensorgrams to provide detailed thermodynamic characterization of biologically relevant interactions. The reversible binding of kynurenic add (KYNA) on human glutamate receptor (GluR1) polypeptide (GluR1(270-300))modified gold surface has been studied at various temperatures under physiological conditions by two-dimensional SPR experiments: The registered sensorgrams were fitted by using different kinetic models without application of any commercial software. Assuming that the association of GluR1(270-3001)-KYNA complex is first order in both reactants, the association (k(a)) and dissociation (k(d)) constants as well as the equilibrium constants (K-A) and the Gibbs free-energy change (Delta G degrees) were given at 10, 20, 30, and 40 degrees C. Moreover, the enthalpy (Delta H degrees = -27.91 kJ mol(-1)), entropy (Delta S degrees = -60.33 J mol(-1) K-1), and heat capacity changes (Delta C-p = -1.28 kJ mol(-1) K-1) of the model receptor ligand system were also calculated using a spreadsheet program. Negative values of Delta G degrees and Delta H degrees indicate the exothermic formation of a stable GluR1(270-300)-KYNA complex, because the \Delta H\ > \T Delta S\ relation suggests an enthalpy-driven binding process. The negative Delta H degrees and AS degrees values strongly support the formation of a salt bridge between KYNA and the positively charged residues of the polypeptide (Arg, Lys) at pH 7.4, confirmed by molecular docking calculations as well.