Abstract
Based on its important physical and pathological function, the androgen receptor (AR) is regarded as a significant drug target. In this report, the authors describe a novel strategy of protein chip technology to screen agonists and antagonists of AR. First, the AR ligand binding domain (AR-LBD) was expressed in Escherichia coli, purified, and then immobilized on a silane-polysaccharide surface of a protein chip. Second, the affinities of methyltestosterone (MT) and fluorescent-labeled testosterone for the AR-LBD protein chip were determined. Third, a converse strategy of the protein chip was tested to evaluate its reliability as a drug screening method. Fourth, a 10,067-compound library was screened to find new ligands of AR. From the results, the Kd of testosterone and the IC50 of MT are consistent with the literature (0.61 vs. 0.49 nM 2.88 vs. 3.90 nM, respectively). The Z′ factor of the high-throughput screening (HTS) method was 0.76, which meets the requirement of drug screening (>0.4). Finally, 3 active ligands of AR were identified with their IC 50 values of 3.63, 2.19, and 1.71 µM, respectively. In summary, the novel strategy of the AR-LBD protein chip was suitable for HTS at the molecular level. (Journal of Biomolecular Screening 2008:276-284)