The association constant of a well-known streptavidin-biotin binding has only been inferred from separately measured kinetic parameters. In a single experiment, we obtained Ka 1 × 1012 M-1 by using a streptavidin-binding aptamer and ligand-displacement isothermal titration calorimetry. This study explores the challenges of determining thermodynamic parameters and the derived equilibrium binding affinity of tight ligand-receptor binding.
- Affinity constant measurement
- Ligand-displacement isothermal titration calorimetry
- Streptavidin-biotin binding
- Thermodynamic parameters