ASSAY METHODS AND COMPOSITIONS USEFUL FOR MEASURING RECEPTORLIGAND BINDING

摘要

This invention provides a system for screening chemical compounds to identify ligands for receptors including G-protein coupled receptors. The invention exploits cells in which the receptor is coupled through a second messenger system to an ion channel that is gated by cyclic nucleotide. Receptor stimulation causes the second messenger system to produce cyclic nucleotide, which results in ion influx through the channel. By measuring ion influx fluorescently, the invention provides a rapid and convenient means for identifying receptor ligands. By providing mixed cell cultures that include cells expressing different receptor types, and by loading into those cells different fluorescent reporters of ion influx, the invention further provides a multiplexed system that accelerates the ligand identification process. Cells useful in the process, and mehtods for exploiting them, are described.