Title
The effect of triterpenoid saponins on pancreatic lipase in vitro: Activity, conformation, kinetics, thermodynamics and morphology
Author
Hongfei Yu, Shengzhao Dong, Liuyang Wang, Yun Liu
Year
2017
Journal
Biochemical Engineering Journal
Abstract
The molecular interactions between pancreatic lipase (PL) and five triterpenoid saponins compounds, including tea saponin, oleanolic acid, betulin, ginsenoside Ro, and ginsenoside Rd, were investigated in vitro through comprehensive evaluation of PL activity, conformation, reaction kinetics, thermodynamics, aggregation morphology and solubility. All tested saponins inhibited PL activity, and their inhibitory ratios showed structure- and concentration-dependence. Tea saponin possessed competitive inhibition against PL activity, and affected PL secondary structure, while other four saponins non-competitively inhibited PL activity and affected PL tertiary structure. However, all tested saponins could statically quench PL fluorescence. Soluble PL-saponins complexes were characterized by AMF, DLS and Bio-Rad method, and PL showed self-assembly phenomenon in the presence of saponins, which possessed a close contribution to the inhibitory ratios. DSC measurement revealed that five tested saponins compounds had variant influence on PL enzyme thermal stability parameters (Tm and △H).
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Chemical stability, Biochemistry