Figure 13 Time course of the lck kinase assay. Concentration of enzyme varies from 0.002 nM to 0.1 nm.

Biomolecular interactions between nuclear receptors and their coactivators are associated with transcriptional regulation and are therefore seen also as an important target for HTS in drug discovery. Ligand binding promotes the association of nuclear receptors with nuclear proteins, such as CREB-binding protein (CBP) and steroid receptor coactivator (SRC-1), which are believed to function as coactivators of transcriptional activity [24]. Following is a description of how HTRF methods were used to characterize and screen for potential agonists to these ligand-dependent interactions.