SPR experiments were performed using a Biacore S200 instrument (GE Healthcare) in 20 mM HEPES pH7.5, 150 mM NaCl, 1 mM TCEP, 0.005% Tween20, 2% DMSO buffer at 10 °C. Biotinylated SBC was immobilized onto a chip surface (the 8inal surface density of biotinylated SBC was approximately 3000-4000 RU). AviTagged-SBC was biotinylated using BirA enzyme as per manufacturer's protocol (Avidity). Compounds were serially diluted in the running buffer and injected individually: contact time 60s, 8low rate 30 μL/min, dissociation time 150s, using a stabilization period of 30s and syringe wash (50% DMSO) between injections. Data analysis was carried out using Biacore Evaluation Software (GE Healthcare). All data were double-referenced for reference surface and blank injection. The processed sensograms were 8it to a steady-state af8inity using a 1:1 binding model for KD estimation.