Synergistic Effect of Kokumi-Active γ-Glutamyl Peptides and L-Glutamate on Enhancing Umami Sensation and Stimulating Cholecystokinin Secretion via T1R1/T1R3 Activation in STC-1 Cells

Authors：Yang, Juan; Liao, Jianhong; Dong, Hao; Huang, Guiying; Bai, Weidong; Tu, Juncai^*; Zeng, Xiaofang

Source：Journal of Agricultural and Food Chemistry, 2022, 70(45): 14395-14402.

DOI：10.1021/acs.jafc.2c04919

• ?-glutamyl peptides
• L-glutamate
• umami taste
• CCK

This study aimed to investigate the synergistic effect of gamma-glutamyl peptides (gamma EL, gamma EV, and gamma E gamma EV) and L-glutamate (MSG) on the activation of the umami receptor (T1R1/T1R3) in relation to enhanced umami taste and promoted cholecystokinin (CCK) secretion. The synergy of gamma-glutamyl peptides and MSG (1-15 mM, 1:1) caused a significant increase in both the umami taste score by 0.218 +/- 0.015-1.216 +/- 0.031 times and the CCK secretion by 41.41 +/- 6.46-201.16 +/- 12.91% when compared to the group treated with individual MSG. The increase in CCK secretion promoted by gamma-glutamyl peptides was only reduced by 11.54 +/- 0.01-45.65 +/- 3.58% after adding yjr CaSR inhibitor (NPS 2143), implying that there were other receptors besides CaSR involved in the stimulation of CCK secretion. The mixture of gamma E gamma EV and MSG synergistically increased the intracellular calcium release by 111.26 +/- 11.94-135.28 +/- 16.60% in STC-1 and 108.47 +/- 7.89-152.33 +/- 26.26% in HEK 293 compared to MSG. The protein expression for T1R1/T1R3 was increased, indicating that the mixture can activate T1R1/T1R3. The amino acids V277, S147, and D190 of T1R3 can be critical for the binding of gamma E gamma EV to T1R3. This is the first report on the synergistic effect of taste-active substances on taste sensation and hormone release via taste receptor activation.

• Institution
  仲恺农业工程学院