The investigation of detection and sensing mechanism of spicy substance based on human TRPV1 channel protein-cell membrane biosensor

The transient receptor potential vanilloid 1 (TRPV1) is a key target for the spicy taste sensor and analgesic drug development. However, the human TRPV1-associated signaling remains to be obscure. In this study, we over expressed human TRPV1 (hTRPV1) in HEK293T cells and explored its signaling activated by spicy substances. A cell membrane biosensor was constructed by using the cells highly expressed hTRPV1 through a layer-by-layer assembly. Our results showed that the activation constants by capsaicin, allicin and sanshool, the active components of chili pepper, garlic and mountain pepper, were Ka, capsaicin = 3.5206 x 10(-16) mol/L, Ka, allicin = 5.0227 x 10(-15) mol/L, Ka, sanshool = 1.7832 x 10(-15) mol/L. Obviously, the order of the sensitivity mediated by hTRPV1 was capsaicin > sanshool > allicin. The affinity values of the three spicy substances with hTRPV1 analyzed by molecular docking simulation also displayed the same law. Most importantly, some amide bonds and their similar groups and even benzene rings of spicy compounds were fund to be critical in the spicy sensing process. In addition, Glu570 in the active pocket of hTRPV1 plays an important role in identifying spicy substances. The elucidation of the detailed mechanism mediated by hTRPV1 in spicy sensing will lay a theoretical foundation to design rational strategies for screening of potential analgesics.

Automated summary

The study investigated the signaling pathway of TRPV1 in response to spicy substances by constructing a cell membrane biosensor. The results showed the activation constants of capsaicin, allicin, and sanshool, with capsaicin being the most sensitive. Molecular docking simulation also confirmed this trend, and identified key structural elements in the spicy sensing process. The role of Glu570 in hTRPV1's active pocket in identifying spicy substances was also highlighted, providing insight for the development of potential analgesics.