Kinase experiment:

Affinity of compounds (e.g., ARV-825) with Bromodomain 1 and 2 of BRD4 is determined with BROMOscan by DiscoverX[1].

ARV-825 is a BRD4 Inhibitor based on PROTAC technology. ARV-825 binds to BD1 and BD2 of BRD4 with Kds of 90 and 28 nM, respectively.

ARV-825 is a hetero-bifunctional proteolysis-targeting chimera (PROTAC) that recruits BRD4 to the E3 ubiquitin ligase cereblon. ARV-825 actively recruits BRD4 to cereblon, resulting in the rapid and efficient degradation of the former via the proteasome. Given that BRD4 and cereblon binding moieties in ARV-825 have Kds of 28-90 nM and ~3 uM to their respective targets, this suggests that ARV-825 acts in a substoichiometric way in mediating BRD4 degradation. ARV-825 treatment results in prolonged BRD4 down-regulation and downstream signaling suppression compared to BRD4 inhibitors[1].

References:
[1]. Lu J, et al. Hijacking the E3 Ubiquitin Ligase Cereblon to Efficiently Target BRD4. Chem Biol. 2015 Jun 18;22(6):755-63.