Determining binding affinity (equilibrium dissociation constant,KD) of UBE2H for the CTLH E3 with Octet biolayer interferometry (BLI). The steady-state responses upon E3 binding to GST-UBE2H (right) were determined based on reference-subtracted BLI sensorgrams shown left and inFigureS4A. The unphosphorylated BC and phosphomimetic S>D UBE2H variants bound too weakly to accurately estimateKDs. SD (n ≥ 3).