Biological Background

The Glucagon-Like Peptide-1 Receptor (GLP-1R) is a class B GPCR central to glucose homeostasis and incretin pathway signaling. GLP-1 (7-37) is the native, bioactive form of GLP-1 that stimulates insulin secretion, suppresses glucagon, and slows gastric emptying.

This bioassay kit supports pharmaceutical and academic researchers developing GLP-1R–targeted therapies for type 2 diabetes, obesity, and metabolic disorders. Applications include drug characterization, potency testing, neutralizing antibody screening, and stability studies.

Eurofins DiscoverX’s PathHunter® GLP-1 (7-37) Bioassay Kit offers ready-to-use CHO-K1 cells engineered for β-arrestin recruitment detection via EFC technology, delivering sensitive, reproducible results for GLP-1R pharmacology profiling.

Product Highlights
  • β-Arrestin recruitment assay: PathHunter® EFC technology for G-protein–independent signal detection
  • Ready-to-use format: Cryopreserved CHO-K1 cells, detection reagents, control agonist, and plates included
  • Versatile applications: Ideal for agonist/antagonist screening, neutralizing antibody detection, and lot release
  • Ideal for full, super, and partial agonists, and assess ligand bias by comparing β-arrestin recruitment versus G-protein signaling profiles.

PathHunter GLP1 (7-37) Bioassay Assay Principle

PathHunter GLP-1R (7-37) Bioassay Assay Principle

β-Arrestin Recruitment and PathHunter® Technology A. GLP-1R ligand-induced β-arrestin-2 recruitment activates signaling cascades independently of G-protein signaling to provide a stoichiometric, non-amplified signal. Upon exendin-4 or other GLP-1R agonist binding, the activated GLP-1R is phosphorylated by GPCR kinases, leading to β-arrestin-2 recruitment. This β-arrestin-2 binding blocks G protein-mediated signaling and results in GLP-1R internalization (endocytosis) and signal desensitization. Subsequently, the GLP-1R is recycled back to the plasma membrane or degraded in the lysosome. This stoichiometric (1 receptor: 1 ligand), non-amplified system requires full ligand occupancy to generate maximum signal, which provides superior sensitivity for detecting GLP-1R antagonists and improved differentiation between partial and full agonists compared to amplified cAMP second messenger systems. By analyzing the GLP-1R β-arrestin pathway, researchers can fine-tune compound characterization when screening antagonists, distinguish between full, super, and partial agonists, and assess ligand bias by comparing β-arrestin recruitment versus G-protein signaling profiles.
B. PathHunte® GLP-1R (7-37) bioassays utilize EFC technology. GLP-1R is fused with the small enzyme donor fragment ProLink™ (PK) and co-expressed in CHO-K1 cells stably expressing β-arrestin-2 fused to the larger enzyme acceptor fragment (EA). GLP-1R activation by exendin-4 or test compounds stimulates β-arrestin-2 recruitment to the PK-tagged receptor, forcing complementation of the enzyme fragments and reconstituting active β-galactosidase enzyme. This interaction produces measurable enzyme activity detected using chemiluminescent PathHunter Detection Reagents. The β-arrestin recruitment assay offers an easy-to-use complement to cAMP and calcium G-protein–dependent pathways, enabling comprehensive GLP-1R compound pharmacology characterization—a universal platform that expands opportunities for developing novel GLP-1–based therapeutics.