Invitrogen™ LanthaScreen™ TR-FRET FXR Coactivator Assay Kit, goat

This kit contains Goat Tb-Anti-GST antibody; other kit components are the same as kit A15140:

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

To assay:
When running the LanthaScreen™ TR-FRET FXR coactivator assay in agonist mode, FXR-LBD is added to ligand test compounds followed by addition of a mixture of the fluorescein-coactivator peptide and Tb-labeled anti-GST antibody. After an incubation period at room temperature, the 520 nm/495 nm TR-FRET ratio is calculated and used to determine the EC50 from a dose response curve of the compound. Based on the biology of the FXR-coactivator peptide interaction, the 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).