【作者】 江宏伟； 周磊； 刘军平； 刘伟；

【Author】 Jiang Hongwei;Zhou Lei;Liu Junping;Liu Wei;State Key Laboratory of Food Science and Resources,Nanchang University;

【机构】 南昌大学食品科学与资源挖掘全国重点实验室；

【摘要】 酚酸是一种潜在的多酚氧化酶(PPO)抑制剂,但目前其自身羧基和体系pH在酚酸抑制多酚氧化酶中扮演的角色仍不清楚。本研究通过多光谱技术、分子对接以及分子动力学模拟技术分析了肉桂酸甲酯、肉桂酸和4-羧基肉桂酸在pH 6.8-5.0条件下对PPO的抑制作用。结果表明,4-羧基肉桂酸对PPO具有最强的抑制作用,其次分别为肉桂酸和肉桂酸甲酯。体系pH的下降可增强三种抑制剂对PPO的抑制作用,且增强程度随羧基数量的增加而增强。肉桂酸甲酯对PPO表现出竞争性抑制作用,而肉桂酸和4-羧基肉桂酸则表现出混合型抑制作用。抑制剂诱导PPO的二级和三级结构发生轻微变化,且酸性pH可增强PPO二、三级结构的改变。分子对接和动力学模拟实验结果表明,4-羧基肉桂酸表现出最强的结合能力,其相互作用力主要围绕在羧基附近,且pH的降低则出现更多的相互作用和更低的结合,从而增强抑制剂与PPO的结合效应。本研究为肉桂酸及其衍生物对酶促褐变的控制和工业应用提供了新的思路。更多还原

【Abstract】 Phenolic acids are potential inhibitors of polyphenol oxidase(PPO),but the effects of their own carboxyl group and the system pH on their inhibition of PPO are still unclear.In this study,the inhibitory effects of methyl cinnamate,cinnamic acid and 4-carboxycinnamic acid on PPO were investigated by multispectral techniques,molecular docking,and molecular dynamics simulation techniques varied from 6.8 to 5.0.Results showed that 4-carboxyl cinnamic acid exhibited the strongest inhibitory effect on PPO,followed by cinnamic acid and methyl cinnamate,respectively.The decreased system pH can enhance the inhibitory effect of the three inhibitors on PPO,and the enhancement degree increasesd with the number of carboxyl groups.Methyl cinnamate exhibited competitive inhibition on PPO,while cinnamic acid and 4-carboxycinnamic acid exhibited mixed-type inhibition.Inhibitors induced slight changes in the secondary and tertiary structures of PPO,which were enhanced by acidic pH.Molecular docking and molecular dynamics simulation results showed that 4-carboxycinnamic acid exhibited the strongest binding ability with the main interaction forces were around carboxyl groups,and acidic pH enhanced the binding effect through more interactions and lower binding energy.This study could provide new insights for the control and industrial application of cinnamic acid and its derivatives in the enzymatic browning of fruits and vegetables.更多还原