title: Investigation on the binding interaction between silybin and pepsin by spectral and molecular docking.
abstract: In this study, the binding mode of silybin with pepsin was investigated by spectroscopic and molecular docking methods. Silybin can interact with pepsin to form a silybin-pepsin complex. The binding constant, number of binding sites and thermodynamic parameters were measured, which indicated that silybin could spontaneously bind with pepsin mainly through hydrophobic interaction with one binding site. Molecular docking results revealed that silybin bound into the pepsin cavity site. Synchronous fluorescence and three-dimensional fluorescence results provide data concerning conformational and some micro-environmental changes of pepsin. Furthermore, in order to reveal whether the binding process can inhibit the activity of pepsin in vivo, the effect of silybin on pepsin activity in rat was investigated. The present study provides direct evidence at a molecular level to show that exposure to silybin could induce changes in the enzyme pepsin structure and function.
authors.affiliation: School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, PR China.
authors.forename: Hua-jin
authors.initials: HJ
authors.lastname: Zeng
authors.affiliation: School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: You
authors.affiliation: School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, PR China.
authors.forename: Hui-li
authors.initials: HL
authors.lastname: Liang
authors.affiliation: School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, PR China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Qi
authors.affiliation: The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, PR China. Electronic address: qulingbo@zzu.edu.cn.
authors.forename: Ran
authors.initials: R
authors.lastname: Yang
authors.affiliation: The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, PR China; School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001, PR China.
authors.forename: Ling-bo
authors.initials: LB
authors.lastname: Qu
mesh_terms: D000818:Animals; D001665:Binding Sites; D002942:Circular Dichroism; D057927:Hydrophobic and Hydrophilic Interactions; D062105:Molecular Docking Simulation; D010434:Pepsin A / Q000008:administration & dosage / Q000737:chemistry*; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D000077385:Silybin; D012838:Silymarin / Q000008:administration & dosage / Q000737:chemistry*; D013057:Spectrum Analysis; D013816:Thermodynamics
chemical_list: D012838:Silymarin; D000077385:Silybin; D010434:Pepsin A
keywords: Enzyme activity; Fluorescence spectroscopy; Molecular docking; Pepsin; Silybin