Patent ID: 7101681

Claim:
An in vitro solid-phase binding assay method for characterizing an agent as a ligand of a nuclear hormone receptor, comprising steps: incubating an in vitro mixture comprising a first, purified nuclear hormone receptor, a peptide sensor and a candidate agent, but not a natural coactivator protein of the first receptor, wherein the sensor consists of a peptide comprising the sequence L 1 X 1 X 2 L 2 L 3 (SEQ ID NO:18) covalently coupled to a detectable label, wherein L 1 –L 3 are independently selected from hydrophobic amino acids and X 1 –X 2 are independently selected from any amino acid and wherein the peptide provides direct, in vitro ligand-dependent binding to the first receptor and is 24 or fewer residues in length, under conditions whereby the peptide of the sensor binds the first receptor to form a first receptor-sensor complex and the complex is immobilized on a solid-phase; measuring an assay binding of the sensor to the first receptor by selectively detecting immobilized first receptor-sensor complexes; and comparing the assay binding with a corresponding control binding, wherein the control binding provides an indication of sensor binding to the first receptor in the absence of the agent, and wherein a greater assay binding than control binding indicates that the agent is a ligand of the receptor.