METHODS FOR DETERMINING PROTEIN LIGAND BINDING

摘要

Provided is a high-throughput differential radial capillary action of ligand assay (DRaCALA) that can be used to detect ligand binding to a protein. The assay is rapid, quantitative and allows detection of protein-ligand interactions for both purified proteins and proteins expressed in whole cells, which eliminates the need for protein purification. The method does not require a wash step, and can be performed without a drying step and without the aid of electrophoretic techniques. The method entails separating unbound ligand from bound ligand by placing a liquid composition that contains or is suspected of containing a protein and a detectably labeled ligand on a dry porous membrane to obtain a location on the membrane that contains the protein. Ligand that is bound to the protein does not migrate away from the location while unbound ligand radially migrates away from the location by capillary action, which separates unbound from bound ligand. The method includes determining whether a ligand binds to one or more proteins and whether a test composition contains a protein.