Conformation change of trypsin induced by acteoside as studied using multiple spectroscopic and molecular docking methods |
| |
Authors: | Zhibing Wu Fengwen Huang Yutao Chen Manjunath D Meti Yu Fan |
| |
Affiliation: | 1. Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China;2. School of Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand |
| |
Abstract: | The interaction of trypsin with acteoside was studied using ultraviolet visible absorption, fluorescence, synchronous fluorescence, circular dichroism techniques, along with molecular docking method. The fluorescence experiments indicated that acteoside quenched the intrinsic fluorescence of trypsin via a combined quenching process (static and dynamic quenching). The binding constant of acteoside to trypsin obtained was 2.50 × 105 L mol?1 at 298 K and the number of binding site was about one under the same experimental condition. The thermodynamic functions ΔH° and ΔS° of the binding process were 8.79 kJ mol?1 and 132.58 J mol?1 K?1, respectively, which indicated that the hydrophobic force was the main acting force between them. Ultraviolet–visible, synchronous fluorescence together with circular dichroism spectra studies demonstrated that the interaction of acteoside with trypsin lead to a loosening and unfolding of the protein backbone with partial β-sheet structures being transformed into α-helix structures. All these experimental results were validated and explained reasonably by docking studies. And the molecular docking results further illustrated that besides hydrophobic forces, hydrogen bonds also played an important role in the stabilization of the acteoside–trypsin complex. Results from this study should be helpful to make full use of acteoside in the food industry and be useful to the design of the drugs for the diseases related to trypsin. |
| |
Keywords: | Acteoside Trypsin Interaction Spectroscopy Docking |
|
|