Mushroom (Agaricus bisporus) polyphenoloxidase inhibited by apigenin: Multi-spectroscopic analyses and computational docking simulation

卷:203

Xiong, Zhiqiang ; Liu, Wei ; Zhou, Lei ; Zou, Liqiang ; Chen, Jun

Nanchang Univ

关键词: Polyphenoloxidase;    Apigenin;    Thermodynamic parameters;    Inhibition mechanism;    Computational docking simulation;   

DOI  :  10.1016/j.foodchem.2016.02.045

学科分类：食品科学和技术

【 摘 要 】

It has been revealed that some polyphenols can prevent enzymatic browning caused by polyphenoloxidase (PPO). Apigenin, widely distributed in many fruits and vegetables, is an important bioactive flavonoid compound. In this study, apigenin exhibited a strong inhibitory activity against PPO, and some reagents had synergistic effect with apigenin on inhibiting PPO. Apigenin inhibited PPO activity reversibly in a mixed-type manner. The fact that inactivation rate constant (k) of PPO increased while activation energy (E-a) and thermodynamic parameters (Delta G, Delta H and Delta S) decreased indicated that the thermosensitivity and stability of PPO decreased. The conformational changes of PPO were revealed by fluorescence emission spectra and circular dichroism. Atomic force microscopy observation suggested that the dimension of PPO molecules was larger after interacting with apigenin. Moreover, computational docking simulation indicated that apigenin bound to PPO and inserted into the hydrophobic cavity of PPO to interact with some amino acid residues. (C) 2016 Elsevier Ltd. All rights reserved.