Abstract In our study, the inhibition mechanism of chlorogenic acid (CGA) on PPO was investigated by enzyme kinetic analysis, fluorescence quenching, thermodynamic parameters analysis, circular dichroism and molecular docking. Our results showed that CGA inhibited PPO activity in a reversible mixed-type manner and Ki was estimated to be 3.577 × 10−4 mol L-1. PPO activity was significantly inactivated by CGA in a dose-dependent manner and IC50 was calculated as 1.55 × 10−4 mol L-1. CGA interacts with PPO and quench its intrinsic fluorescence. Furthermore, results indicated that CGA bound with PPO by hydrophobic interaction. In addition, CGA changed the hydrogen bonding network of PPO and resulted in rearragement of secondary structure. The molecular docking results suggested that CGA bound to active site of PPO. Importantly, the efficacy of CGA inhibiting the enzymatic browning of fresh-cut potato slices was confirmed by the inhibition of PPO. Therefore, based on the inhibition of PPO, CGA might represent a new type of inhibitor for fresh-cut potatoes.

中文翻译：

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绿原酸对鲜切马铃薯多酚氧化酶及褐变的抑制作用

摘要 本研究通过酶动力学分析、荧光猝灭、热力学参数分析、圆二色性分析和分子对接研究绿原酸(CGA)对PPO的抑制机制。我们的结果表明，CGA 以可逆的混合型方式抑制 PPO 活性，Ki 估计为 3.577 × 10-4 mol L-1。CGA 以剂量依赖性方式显着灭活 PPO 活性，IC50 计算为 1.55 × 10-4 mol L-1。CGA 与 PPO 相互作用并淬灭其固有荧光。此外，结果表明 CGA 通过疏水相互作用与 PPO 结合。此外，CGA 改变了 PPO 的氢键网络，导致二级结构的重新排列。分子对接结果表明CGA与PPO的活性位点结合。重要的，CGA 抑制鲜切马铃薯切片酶促褐变的功效通过抑制 PPO 得到证实。因此，基于对PPO的抑制作用，CGA可能是一种新型的鲜切马铃薯抑制剂。