Production of Olfactory Receptors and Nanovesicles Using Heterologous Cell Systems for Bioelectronic Nose - Bioelectronic Nose: Integration of Biotechnology and Nanotechnology - page 149

Fig. 9.5 a SDS-PAGE of the hTAS2R38, human taste receptor protein, expressed in E. coli . PAV
and AVI represent the receptor protein types of tasters and non-tasters, respectively. b Western blot
analysis of the hTAS2R38 expressed in E. coli . The dark bands marked by the arrow indicate the
expression of human taste receptor protein. c Schematic diagram showing the structure of human
taste receptor functionalized swCNT. d Response of PAV-functionalized, AVI-functionalized
and bare CNT-FETs to PTC. (Reprinted from Ref. [ 79 ] with permission from Royal Society of
Chemistry.)

9.2.3 Production of Taste Receptors and Other Receptors

from Bacterial Cells

These approaches developed for the bioelectronic nose were applied to the develop-
ment of bioelectronic tongues utilizing taste receptors, and opened up opportunities
for the development of various biosensors using GPCRs as recognition elements.
Advances in the production of GPCR using bacterial cells offered efficient recogni-
tion for the development of high-performance biosensors, including bioelectronic
tongues, neurotransmitter sensor, and peptide hormone sensor. The human bitter
taste receptors, hTAS2R38s, were successfully produced from inclusion bodies in
E. coli , and utilized as recognition elements for the development of a bioelectron-
ic tongue with the integration of a nanomaterial-based sensor platform including
single-walled carbon nanotube (swCNT) [ 79 ], and conducting polymer nanotube
(CPNT) [ 81 ] field effect transistor (FET). It is known that sequence variants in
the hTAS2R38 gene correlate with different bitterness recognition for tasting bit-
ter compound phenylthiocarbamide (PTC) and propylthiouracil (PROP), and this