A Surface Plasmon Resonance Spectroscopy Method for Characterizing Small-Molecule Binding to Nerve Growth Factor

Small-molecule inhibitors have been previously investigated to identify possible therapeutics for the treatment of chronic pain. In the present study, known nerve growth factor (NGF) inhibitors identified by 125I-NGF binding were characterized using affinity and binding evaluations by surface plasmon resonance (SPR) spectroscopy. A novel strategy for characterizing NGF inhibitors was used to determine the binding affinity (KD) and saturation ability of each compound with immobilized NGF. Seventy-four percent of compounds screened demonstrated a positive binding event to NGF. A KD less than 10 μM and a percent saturation greater than 50% were used as thresholds to identify inhibitors that would warrant further investigation. This study details for the first time a methodology that can be used to directly characterize the binding event between small-molecule inhibitors and NGF.