A novel label-free live-cell biosensor for G-protein-coupled receptor functional assay with enhanced sensitivity.

This study developed a surface plasmon resonance (SPR)-based live-cell biosensor with enhanced sensitivity for label-free ligand binding assay of G-protein-coupled receptors (GPCRs). The β2-adrenoceptor was heterologously expressed in human embryonic kidney-293 cells. The specific ligand binding function of expressed β2-adrenoceptor was monitored by SPR via refractive index measurement. The results indicate the expressed β2-adrenoceptor can respond to isoprenaline with high specificity. The SPR signals can be enhanced more than three times by the use of LY294002. This biosensor can be applied in the functional assay of GPCRs by detecting the specific interactions between GPCRs and their target ligands.