Abstract: Methods for detecting G-protein coupled receptor (GPCR) activity; methods for assaying GPCR activity; and methods for screening for GPCR ligands, G-protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process are described. Included are methods for expanding ICAST technologies for assaying GPCR activity with applications for ligand fishing, and agonist or antagonist screening. These methods include: engineering seronine/threonine phosphorylation sites into known or orphan GPCR open reading frames in order to increase the affinity of arrestin for the activated form of the GPCR or to increase the reside time of arrestin on the activated GPCR; engineering mutant arrestin proteins that bind to activated GPCRs in the absence of G-protein coupled receptor kinases which may be limiting; and engineering mutant super arrestin proteins that have an increased affinity for activated GPCRs with or without phosphorylation.

Abstract: Methods for detecting G-protein coupled receptor (GPCR) activity; methods for assaying GPCR activity; and methods for screening for GPCR ligands, G-protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process are described. Included are methods for expanding ICAST technologies for assaying GPCR activity with applications for ligand fishing, and agonist or antagonist screening. These methods include: engineering seronine/threonine phosphorylation sites into known or orphan GPCR open reading frames in order to increase the affinity of arrestin for the activated form of the GPCR or to increase the reside time of arrestin on the activated GPCR; engineering mutant arrestin proteins that bind to activated GPCRs in the absence of G-protein coupled receptor kinases which may be limiting; and engineering mutant super arrestin proteins that have an increased affinity for activated GPCRs with or without phosphorylation.

Abstract: Methods for detecting G-protein coupled receptor (GPCR) activity; methods of assaying GPCR activity; and methods of screening for GPCR ligands, G-protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process are described.

Abstract: Methods for detecting G-protein coupled receptor (GPCR) activity; methods for assaying GPCR activity; and methods for screening for GPCR ligands, G-protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process are described. Included are methods for expanding ICAST technologies for assaying GPCR activity with applications for ligand fishing, and agonist or antagonist screening. These methods include: engineering seronine/threonine phosphorylation sites into known or orphan GPCR open reading frames in order to increase the affinity of arrestin for the activated form of the GPCR or to increase the reside time of arrestin on the activated GPCR; engineering mutant arrestin proteins that bind to activated GPCRs in the absence of G-protein coupled receptor kinases which may be limiting; and engineering mutant super arrestin proteins that have an increased affinity for activated GPCRs with or without phosphorylation.

Abstract: Methods for detecting G-protein coupled receptor (GPCR) activity; methods for assaying GPCR activity; and methods for screening for GPCR ligands, G-protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process are described. Included are methods for expanding ICAST technologies for assaying GPCR activity with applications for ligand fishing, and agonist or antagonist screening. These methods include: engineering seronine/threonine phosphorylation sites into known or orphan GPCR open reading frames in order to increase the affinity of arrestin for the activated form of the GPCR or to increase the reside time of arrestin on the activated GPCR; engineering mutant arrestin proteins that bind to activated GPCRs in the absence of G-protein coupled receptor kinases which may be limiting; and engineering mutant super arrestin proteins that have an increased affinity for activated GPCRs with or without phosphorylation.

Abstract: Heterogenous and homogenous assays are provided for the detection of protease inhibitory activity in a sample or target compound, taking advantage of the chemiluminescent characteristics of 1,2-dioxetanes. In the heterogenous assay, a peptide bearing a cleavage site for the protease of interest is provided with a first member of a first ligand binding pair at one end, and a first member of a second ligand binding pair at the other end. The other member of the first ligand binding pair is attached to a surface, which binds the peptide, or protease substrate, to the surface. The peptide substrate is combined with the protease and target compound or sample. Substrate cleavage, if not inhibited, is allowed to occur, and any unbound cleaved fragments are removed. An enzyme complexed with the second member of the second ligand binding pair is added, and allowed to bind to any of the (uncleaved) first member of the second ligand binding pair remaining.

Abstract: Heterogenous and homogenous assays are provided for the detection of protease inhibitory activity in a sample or target compound, taking advantage of the chemiluminescent characteristics of 1,2-dioxetanes. In the heterogenous assay, a peptide bearing a cleavage site for the protease of interest is provided with a first member of a first ligand binding pair at one end, and a first member of a second ligand binding pair at the other end. The other member of the first ligand binding pair is attached to a surface, which binds the peptide, or protease substrate, to the surface. The peptide substrate is combined with the protease and target compound or sample. Substrate cleavage, if not inhibited, is allowed to occur, and any unbound cleaved fragments are removed. An enzyme complexed with the second member of the second ligand binding pair is added, and allowed to bind to any of the (uncleaved) first member of the second ligand binding pair remaining.