Isothermal titration calorimetry (ITC) binding assay to quantify affinity (KD) of Art22-9 degron for Gid1057-292 substrate-binding domain. The raw ITC results (top) were integrated to calculate the amount of heat released (∆H) during every injection of a peptide and plotted as a function of peptide:protein molar ratio (bottom). Fitting of the obtained data points to the binding model served to determine KD and stoichiometry of the binding reaction (N). 