A fully automated [35S]GTPgammaS scintillation proximity assay for the high-throughput screening of Gi-linked G protein-coupled receptors

Assay Drug Dev Technol. 2003 Apr;1(2):261-73. doi: 10.1089/15406580360545071.


The diversity of physiological functions mediated by the GPCR superfamily provides a rich source of molecular targets for drug discovery programs. Consequently, a variety of assays have been designed to identify lead molecules based on ligand binding or receptor function. In one of these, the binding of [(35)S]GTPgammaS, a nonhydrolyzable analogue of GTP, to receptor-activated G-protein alpha subunits represents a unique functional assay for GPCRs and is well suited for use with automated HTS. Here we compare [(35)S]GTPgammaS scintillation proximity binding assays for two different G(i)-coupled GPCRs, and describe their implementation with automated high-throughput systems.

MeSH terms

  • Automation / methods*
  • Biological Assay / methods
  • Combinatorial Chemistry Techniques / methods
  • Guanosine 5'-O-(3-Thiotriphosphate) / analysis*
  • Guanosine 5'-O-(3-Thiotriphosphate) / metabolism
  • Radioligand Assay / methods
  • Receptors, G-Protein-Coupled / analysis*
  • Scintillation Counting / methods*
  • Sulfur Radioisotopes* / metabolism


  • Receptors, G-Protein-Coupled
  • Sulfur Radioisotopes
  • Guanosine 5'-O-(3-Thiotriphosphate)