Different inhibition mechanisms of gentisic acid and cyaniding-3-O-glucoside on polyphenoloxidase
Different inhibition mechanisms of gentisic acid and cyaniding-3-O-glucoside on polyphenoloxidase
复制标题
龙胆酸和氰化-3-O-葡萄糖苷对多酚氧化酶的不同抑制机制
DOI：
10.1016/j.foodchem.2017.05.010
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发表时间：
2017
期刊：
影响因子：
8.8
通讯作者：
Zou Liqiang
中科院分区：
文献类型：
--
作者：
Zhou Lei;Xiong Zhiqiang;Liu Wei;Zou Liqiang
龙胆酸和矢车菊素-3-O-葡萄糖苷是重要的生物活性多酚，广泛分布于多种水果和谷物中。采用动力学研究、光谱分析和计算机模拟等方法，比较了龙胆酸和矢车菊素-3-O-葡萄糖苷对蘑菇多酚氧化酶（PPO）的抑制作用及其机理。矢车菊素-3-O-葡萄糖苷对多酚氧化酶的抑制作用明显强于龙胆酸。龙胆酸对PPO的抑制作用为可逆混合型，矢车菊素-3-O-葡萄糖苷为不可逆抑制剂。龙胆酸和矢车菊素-3-O-葡萄糖苷使PPO的热失活变得容易，并引起PPO构象发生明显变化。与龙胆酸相比，矢车菊素-3-O-葡萄糖苷对PPO的热失活和构象的影响更强。分子对接结果表明，龙胆酸通过氢键、π-π堆积和货车范德华力与PPO活性中心结合。而花青素-3-O-葡萄糖苷可能与PPO中的Met或Cys通过共价键发生不可逆的相互作用。
Gentisic acid and cyanidin-3-O-glucoside are important bioactive polyphenols which are widely distributed in many fruits and cereals. In this work, kinetic study, spectral analysis and computational simulation were used to compare the inhibitory effects and inhibition mechanisms of gentisic acid and cyanidin-3-O-glucoside on mushroom polyphenoloxidase (PPO). The inhibitory effect of cyanidin-3-O-glucoside on PPO was much stronger than that of gentisic acid. Gentisic acid inhibited PPO in a reversible mixed-type manner while cyanidin-3-O-glucoside was an irreversible inhibitor. Gentisic acid and cyanidin-3-O-glucoside made the thermal inactivation of PPO easier, and induced apparent conformational changes of PPO. Compared with gentisic acid, cyanidin-3-O-glucoside had stronger effects on the thermal inactivation and conformation of PPO. Molecular docking results revealed gentisic acid bound to the active site of PPO by hydrogen bonding, π–π stacking and van der Waals forces. However, cyanidin-3-O-glucoside might irreversibly interact with the Met or Cys in PPO by covalent bonds.