Comparison of weak affinity chromatography and surface plasmon resonance in determining affinity of small molecules

In this study, we compared affinity data from surface plasmon resonance (SPR) and weak affinity chromatography (WAC), two established techniques for determination of weak affinity (mM-μM) small molecule-protein interactions. In the current comparison, thrombin was used as target protein. In WAC the affinity constant (KD) was determined from retention times, and in SPR it was determined by Langmuir isotherm fitting of steady-state responses. Results indicate a strong correlation between the two methods (R2 = 0.995, P < 0.0001).