College of Food Science and Technology, Bohai University, Food Safety Key Laboratory of Liaoning Province, National & Local Joint Engineering Research Center for Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou 121013, China.
College of Food Science and Technology, Bohai University, Food Safety Key Laboratory of Liaoning Province, National & Local Joint Engineering Research Center for Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou 121013, China; Institute of Ocean Research of Bohai University, Jinzhou 121013, China.
Int J Biol Macromol. 2024 Mar;261(Pt 2):129794. doi: 10.1016/j.ijbiomac.2024.129794. Epub 2024 Feb 1.
Inhibition of acid phosphatase, which significantly contributes to inosine 5'-monophosphate (IMP) degradation, is crucial for preventing flavor deterioration of aquatic products during storage. In this study, the inhibitory effect of epicatechin gallate (ECG) on the activity of acid phosphatase isozymes (ACPI and ACPII) was analyzed using inhibition kinetics, fluorescence spectroscopy, isothermal titration calorimetry, and molecular simulation. ACPI and ACPII with molecular weights of 59.5 and 37.3 kDa, respectively, were purified from rainbow trout liver. ECG reversibly inhibited ACPI and ACPII activities via mixed-type inhibition, with half maximal inhibitory concentration (IC) of 0.24 ± 0.01 mmol/L and 0.27 ± 0.03 mmol/L, respectively. Fluorescence spectra indicated that ECG statically quenched the intrinsic fluorescence of ACPI and ACPII. ECG could spontaneously bind to ACPI and ACPII through hydrogen bonding and van der Waals forces and exhibited a higher affinity for ACPI than for ACPII. In addition, molecular dynamic simulation revealed that ECG-ACPI and ECG-ACPII complexes were relatively stable during the entire simulation process. Our findings provide a theoretical basis for the use of ECG as an inhibitor of ACP to improve the flavor of aquatic products.
抑制酸性磷酸酶对于防止水产品在储存过程中风味恶化至关重要，因为酸性磷酸酶会显著促进肌苷 5'-单磷酸（IMP）的降解。在这项研究中，我们使用抑制动力学、荧光光谱、等温热力学滴定和分子模拟分析了表儿茶素没食子酸酯（ECG）对酸性磷酸酶同工酶（ACPI 和 ACPII）活性的抑制作用。分子量分别为 59.5 和 37.3 kDa 的 ACPI 和 ACPII 从虹鳟鱼肝脏中纯化得到。ECG 通过混合抑制可逆地抑制 ACPI 和 ACPII 的活性，其半最大抑制浓度（IC）分别为 0.24±0.01 mmol/L 和 0.27±0.03 mmol/L。荧光光谱表明，ECG 静态猝灭了 ACPI 和 ACPII 的内源荧光。ECG 可以通过氢键和范德华力自发结合到 ACPI 和 ACPII 上，并且对 ACPI 的亲和力高于 ACPII。此外，分子动力学模拟表明，在整个模拟过程中，ECG-ACPI 和 ECG-ACPII 复合物相对稳定。我们的研究结果为将 ECG 用作 ACP 的抑制剂以改善水产品的风味提供了理论依据。
