A kinetic study of bitter taste receptor sensing using immobilized porcine taste bud tissues

At present, developing an efficient assay method for truly reflecting the real feelings of gustatory tissues is of great importance. In this study, a novel biosensor was fabricated to investigate the kinetic characteristics of the receptors in taste bud tissues sensing bitter substances for the first time. Porcine taste bud tissues were used as the sensing elements, and the sandwich-type sensing membrane was fixed onto a glassy carbon electrode for assembling the biosensor. With the developed sensor, the response currents induced by sucrose octaacetate, denatonium benzoate, and quercetin stimulating corresponding receptors were determined. The results demonstrated that the interaction between the analyst with their receptors were fitting to hyperbola (R²=0.9776, 0.9980 and 0.9601), and the activation constants were 8.748×10^-15mol/L, 1.429×10^-12mol/L, 6.613×10^-14mol/L, respectively. The average number of receptors per cell was calculated as 1.75, 28.58, and 13.23, while the signal amplification factors were 1.08×10⁴, 2.89×10³ and 9.76×10⁴. These suggest that the sensor can be used to quantitatively describe the interaction characteristics of cells or tissue receptors with their ligands, the role of cellular signaling cascade, the number of receptors, and the signal transmission pathways.