Method for assaying compounds or agents for ability to displace potent ligands of hematopoietic prostaglandin D synthase

An exemplary embodiment may be directed to a fluorescence polarization assay that screens compounds or agents for their affinity to hematopoietic prostaglandin D synthase (H-PGDS) based on their ability to displace a fluorophore-containing detection analyte bound to an enzyme comprising the primary amino acid sequence of H-PGDS. Another exemplary embodiment utilizes an enzyme having a maltose binding protein amino-acid sequence fused with an N-terminus of the enzyme.