Structural Characterization of Lipu Taro Globulin and Its Glucose Metabolism Activity on HepG2 Cells

In order to characterize the basic properties of Lipu taro globulin and explore the mechanism of the effect on cell glucose metabolism globulin, thermal stability, amino acid composition and secondary structure composition were determined, and the effects of different concentrations of Lipu taro globulin on glucose consumption, liver glycogen content, hexokinase and pyruvate kinase activities of insulin resistant HepG2 cells were studied. The results showed that the denaturation temperature of Lipu taro globulin was 79.30±1.36 ℃, and the corresponding enthalpy values was 7.46±0.53 J/g. The globulin was rich of aspartic acid and glutamic acid, with an amino acid score of 103.10%. The secondary structure composition: The contents of β-sheet , random coil, β-turn and α-helix were 39.42%～42.14%, 26.34%～31.38%, 18.25%～24.16% and 5.04%～13.27%. Lipu taro globulin could affect glucose metabolism of insulin resistant cells, compared with the control group, Lipu taro globulin high dose group (500 μg/mL) increased glucose consumption by 40.62%±0.98%, increased liver glycogen content by 26.35%±1.13%, increased hexokinase activity by 54.63%±2.48% and increased pyruvate kinase activity by 44.29%±2.64%. In conclusion, Lipu taro globulin could promote cell glucose absorption, increase liver glycogen synthesis and improve the activities of hexokinase and pyruvate kinase, thus affecting glucose metabolism, the mechanism of action might be related to promoting insulin secretion and enhancing glycolysis.