Revisiting the streptavidin–biotin binding by using an aptamer and displacement isothermal calorimetry titration

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 K a 1  ×  10 12  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. Copyright © 2015 John Wiley & Sons, Ltd.