The α values obtained by F NMR correlated well with those previously obtained by other biophysical methods (Table ). For PROTACs with negative cooperativity all α were below 1 and the same trend was observed, with MZP-55 possessing the highest α of the set and MZP-61 forming the least cooperative complex. Regarding the MZ1-induced complexes the results followed a similar trend previously reported SPR and FP measurements. The lowest α were obtained with Brd2(1) and Brd4(1), while the most cooperative complexes were those with Brd2(2) and Brd4(2).