In recent years, advances in the development of chemical inducers of protein degradation has gained much attention, especially regarding their applications as novel chemical probes and therapeutics. Small molecules capable of inducing the degradation of a disease-relevant protein can present several advantages over inhibitors more routinely used in drug discovery campaigns. Due to the catalytic mode-of-action of degraders, the desired effects can be achieved at lower drug concentration and less frequent dosages, potentially reducing toxicity and off-targets. The most common strategy for the development of degraders consists in chemically linking an E3 ligase ligand with a binder of the target protein. These bifunctional molecules are commonly referred as proteolysis targeted chimeras (PROTACs). Currently, several PROTACs are in clinical trials for the treatment of various cancers, highlighting the therapeutic potential of this class of molecules. Bifunctional PROTAC molecules can engage their protein binding partners individually as binary complexes, but their functional activity is dependent on simultaneous engagement of both partners as a ternary complex. Biophysical and structural studies have revealed that new interactions between the E3 ligase and the target protein can be formed within the ternary complex. This finding demonstrated that PROTACs are capable of inducing de novo protein-protein interactions in a similar fashion as molecular glue degraders (e.g. thalidomide and indisulam). A notable example of PROTACs inducing protein-protein interactions is MZ1, designed to promote the ubiquitination of members of the bromodomain and extraterminal domain (BET) protein family by bringing them in close proximity to the von Hippel-Lindau (VHL) E3 ligase. In spite of being designed from a pan-selective BET inhibitor, MZ1 preferentially induced the degradation of Brd4 (bromodomain-containing protein 4). Further studies revealed that a major contributor for this selective degradation profile is the high positive cooperativity (α) of the ternary complex formed with the second bromodomain of Brd4(2). The crystal structure of this complex revealed extensive contacts between VHL and Brd4(2), leading to a greater stability and longer half-life of the ternary complex with Brd4(2) when compared to those formed with other BET bromodomains, that correlated with greater ubiquitination and faster initial rates of degradation of Brd4. This correlation between biophysical ternary complex formation and cellular activity motivates the development of methods for monitoring and measuring the α of ternary complexes, aiding the rational design of effective degraders. In our initial study, α was derived from binding affinities measured by isothermal titration calorimetry (ITC), an approach rich in thermodynamic information but timeconsuming and sample-demanding. Other biophysical methods used to study PROTAC-ternary complexes include fluorescence polarisation (FP), TR-FRET, surface plasmon resonance (SPR) and native mass spectrometry. However, no nuclear magnetic resonance (NMR) based methods have been reported so far to monitor cooperativity of PROTAC-ternary complexes. NMR experiments are well established methods to detect both weak-and high-affinity binders in drug discovery campaigns. Expanding the range of applications of NMR to study PROTAC-induced complexes could therefore be a beneficial addition to the PROTAC assays toolkit.