Tripeptide Containing Selenium with Glutathione Peroxidase Activity

Six selenium-containing tripeptides (QUW, QWU, WQU, WUQ, UWQ and UQW) were synthesized by solid-phase synthesis technology based on the catalytic triad of native glutathione peroxidase (GPx). The GPx activities and the kinetics of the tripeptide were determined by the enzyme coupling method. The effects of tripeptide on HepG2 cells growth and migration were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, wound assay and Western blot method. The results showed that the GPx activity of the tripeptide with U at the amino terminal was higher than that of U at the middle position or the carboxyl terminal. Among the six tripeptide, the activity of UWQ catalyzed by glutathione (GSH) reduced by hydrogen peroxide (H2O2) was higher than those of other tripeptides, and its catalytic mechanism was Ping-Pong mechanism. UWQ can dosedependently discrease migration speed of HepG2 cells to exercise, and reduce the invasion and metastasis of HepG2 cells.