title: Investigation on interaction between Ligupurpuroside A and pepsin by spectroscopic and docking methods.
abstract: Ligupurpuroside A is one of the major glycoside in Ku-Din-Cha, a type of Chinese functional tea. In order to better understand its digestion and metabolism in humans, the interaction between Ligupurpuroside A and pepsin has been investigated by fluorescence spectra, UV-vis absorption spectra and synchronous fluorescence spectra along with molecular docking method. The fluorescence experiments indicate that Ligupurpuroside A can effectively quench the intrinsic fluorescence of pepsin through a combined quenching way at the low concentration of Ligupurpuroside A, and a static quenching procedure at the high concentration. The binding constant, binding sites of Ligupurpuroside A with pepsin have been calculated. The thermodynamic analysis suggests that non-covalent reactions, including electrostatic force, hydrophobic interaction and hydrogen bond are the main forces stabilizing the complex. According to the Förster's non-radiation energy transfer theory, the binding distance between pepsin and Ligupurpuroside A was calculated to be 3.15 nm, which implies that energy transfer occurs between pepsin and Ligupurpuroside A. Conformation change of pepsin was observed from UV-vis absorption spectra and synchronous fluorescence spectra under experimental conditions. In addition, all these experimental results have been validated by the protein-ligand docking studies which show that Ligupurpuroside A is located in the cleft between the domains of pepsin.
authors: College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen 518060, China.
authors: Liangliang
authors: L
authors: Shen
authors: College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen 518060, China. Electronic address: xuhong@szu.edu.cn.
authors: Hong
authors: H
authors: Xu
authors: College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen 518060, China.
authors: Fengwen
authors: F
authors: Huang
authors: College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen 518060, China.
authors: Yi
authors: Y
authors: Li
authors: College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen 518060, China.
authors: Huafeng
authors: H
authors: Xiao
authors: College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen 518060, China.
authors: Zhen
authors: Z
authors: Yang
authors: College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen 518060, China.
authors: Zhangli
authors: Z
authors: Hu
authors: School of Medicine, Shenzhen University, Shenzhen 518060, China. Electronic address: hezhendan@126.com.
authors: Zhendan
authors: Z
authors: He
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors: Zheling
authors: Z
authors: Zeng
authors: Center of Inspection and Quarantine of Shenzhen Entry & Exit Animal, Plant & Food, Shenzhen 518000, China.
authors: Yinong
authors: Y
authors: Li
mesh_terms: D000818:Animals; D001665:Binding Sites; D004735:Energy Transfer; D006027:Glycosides / Q000737:chemistry*; D007700:Kinetics; D008968:Molecular Conformation; D062105:Molecular Docking Simulation / Q000379:methods*; D010434:Pepsin A / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D034421:Sus scrofa; D013696:Temperature
chemical_list: D006027:Glycosides; C000598661:ligupurpuroside A; D010434:Pepsin A
keywords: Interaction; Ligupurpuroside A; Molecular docking; Pepsin; Spectroscopy