DTect-AllTM is a binding technology designed for the identification of every compounds interacting with the 7-transmembrane (7-TM) domain of engineered GPCRs. The corresponding FRET-based assays, developed on stable cell lines, are screened in presence of fluorescent probes that act as surrogate markers of the GPCR change of conformation.
The external truncation (STEP 1) focuses the test on potential allosteric modulator sites by removing all or part of the endogenous ligand binding site (orthosteric site). A fluorescent protein is fused to the GPCR to create the energy donor of the FRET detection system.
The energy acceptor of the detection system is made of a fluorescent probe interacting non-selectively with extracellular loops or 7-TM domain. The probe is obtained by screening a proprietary collection of more than 5,000 GPCR-frequent-hitter fluorescent molecules enabling the selection of a probe suitable for FRET interaction (STEP 2). Domain’s probe collection allows assay development for every GPCR, including orphans. The double labeling system detects GPCR-interacting ligand only on-target.
The resulting binding assay is screened to identify compounds disturbing FRET-signal by conformational change of the GPCR 7-TM (STEP 3). Most interesting GPCR-interacting ligands are not competitively displacing the probe and bind at any site on the receptor surface.