Surface plasmon resonance for the detection of binding of MLN-4760 to ACE2: In order to directly probe the binding kinetics of small molecules to ACE2, relatively high levels of the target on the sensor chip are needed (due to the large difference in mass between these molecules and the protein target). To achieve these higher levels, ACE2 was covalently attached to the sensor chip via amine coupling. To validate that the target is binding competent once immobilized to the sensor chip, the binding of ACE2 inhibitor MLN-4760 was measured using a kinetic titration (single-cycle kinetics). The KD value of ~1 nM is consistent with the IC50 value of 440 pM.
To learn more about surface plasmon resonance (SPR), please visit our biophysics assays webpage.