The VFT domain of T1R1 taste receptor expressed in insect cells recognizes different umami substances

Taste receptor type 1 member 1 (T1R1) is an essential component of the human umami receptor, responsible for detecting umami substances. The T1R1 receptor consists of three primary domains: the venus flytrap (VFT) domain, the cysteine-rich Domain (CRD), and the seven-transmembrane domain (TMD). Previous studies have highlighted the T1R1-VFT domain as a critical component in umami flavor recognition. The T1R1-VFT protein was successfully expressed using a baculovirus-insect cell system and subsequently purified. Additionally, umami peptides were synthesized through solid-phase peptide synthesis (SPPS). Biolayer interferometry (BLI) was utilized to determine the affinity constants between T1R1-VFT and various umami-related compounds, including L-glutamate, umami dipeptides, and umami peptides. Sensory-assessed umami peptides, along with L-glutamate and dipeptides, exhibited similar dissociation constants. These findings confirm that the expressed and purified T1R1-VFT retains its biological activity. • The T1R1-VFT is expressed in the baculovirus-insect cell system, producing a correctly folded protein. • Extraction and purification of T1R1-VFT with mild detergents preserve its biological activity for functional assays. • Bio-layer interferometry (quantitatively measures binding affinities between T1R1-VFT and various umami substances.