This kit contains Rabbit Tb-Anti-GST antibody; other kit components are the same as kit PV4541:

The LanthaScreen™ TR-FRET Estrogen Receptor beta Coactivator Assay Kit provides a sensitive and robust method for high-throughput screening of potential ER beta ligands as agonists or antagonists of ligand-dependent coactivator recruitment. The kit uses a terbium (Tb)-labeled anti-GST antibody, a fluorescein-labeled coactivator peptide, and a ER beta ligand-binding domain (ER beta-LBD) that is tagged with glutathione-S-transferase (GST), in a homogenous mix-and-read assay format.

Agonist mode
To run the LanthaScreen™ TR-FRET Estrogen Receptor beta Coactivator Assay in agonist mode (to identify agonist compounds), ER beta-LBD is added to ligand test compounds followed by addition of a mixture of the fluorescein-coactivator peptide and Tb-anti-GST antibody. After room temperature incubation, the TR-FRET 520:495 emission ratio is calculated and used to determine the EC50 from a dose response curve of the compound. Based upon the biology of the ER beta-coactivator peptide interaction, this ligand EC50 is a composite value representing the amount of ligand required to bind to receptor, effect a conformational change, and recruit coactivator peptide (Figure 1).

Antagonist mode
When the LanthaScreen™ TR-FRET Estrogen Receptor beta Coactivator Assay Kit is run in antagonist mode (to identify antagonist compounds), ER beta-LBD is added to ligand test compounds followed by addition of a mixture of agonist, fluorescein-coactivator peptide, and Tb-anti-GST antibody. The concentration of agonist used in this mode is the EC80 concentration as determined by first running the assay in agonist mode (Figure 2).

Contents and Storage:
The LanthaScreen™ TR-FRET ER beta Coactivator Assay Kit contains ER beta-LBD (GST) protein, fluorescein-labeled PGC1a coactivator peptide, Tb-anti-GST antibody, and buffers. Store components as indicated in the assay protocol (-80°C, -20°C, or +4°C).