Selective nonpeptidic fluorescent ligands for oxytocin receptor: design, synthesis, and application to time-resolved FRET binding assay.

The design and the synthesis of the first high-affinity fluorescent ligands for oxytocin receptor (OTR) are described. These compounds enabled the development of a TR-FRET based assay for OTR, readily amenable to high throughput screening. The validation of the assay was achieved by competition experiments with both peptide and nonpeptide OTR ligands as competitors. These probes represent the first selective fluorescent ligands for the oxytocin G protein-coupled receptor.