Immobilization of arrestin-3 on different biosensor platforms for evaluating GPCR binding

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• G protein-coupled receptors (GPCRs) are crucial drug targets, but traditional cell-based assays are complex.
• Biosensor assays offer a direct and specific alternative for monitoring GPCR-protein interactions.

Purpose of the Study:

• To develop and validate label-free biosensor assays for real-time detection of GPCR-protein binding.
• To quantify the binding kinetics between arrestin-3 proteins and the JSR1 GPCR.

Main Methods:

• Stable immobilization of histidine-tagged arrestin-3 proteins (wild type and mutants) on NTA(Ni2+)-coated sensors.
• Utilized biolayer interferometry (BLI), surface plasmon resonance (SPR), and quartz crystal microbalance with dissipation (QCM-D) for label-free detection.
• Real-time monitoring of interactions between arrestin-3 variants and JSR1 GPCR.

Main Results:

• Successfully quantified binding affinity, association, and dissociation rate constants for arrestin-3 variants with JSR1.
• Demonstrated that JSR1 exhibits the strongest binding affinity to the arrestin-3 mutant Y (R393E).
• Confirmed the utility of surface-based biosensing for label-free GPCR interaction analysis.

Conclusions:

• Introduced direct, label-free biosensor-based screening for GPCR interactions.
• These methods are adaptable for diverse GPCRs and potential drug compounds.
• Highlight the potential of arrestin mutants in GPCR research and drug discovery.