Ao Le, Liu Panhang, Wu Annan, Zhao Jing, Hu Xiaosong
College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
China National Engineering Research Center for Fruit and Vegetable Processing, Beijing 100083, China.
Foods. 2021 Nov 16;10(11):2813. doi: 10.3390/foods10112813.
(1) Background: Protein-polyphenol interactions have been widely studied regarding their influence on the properties of both protein and the ligands. As an important protein material in the food industry, soybean protein isolate (SPI) experiences interesting changes through polyphenols binding. (2) Methods: In this study, a molecular docking and virtual screening method was established to evaluate the SPI-polyphenol interaction. A compound library composed of 33 commonly found food source polyphenols was used in virtual screening. The binding capacity of top-ranking polyphenols (rutin, procyanidin, cyanidin chloride, quercetin) was validated and compared by fluorescence assays. (3) Results: Four out of five top-ranking polyphenols in virtual screening were flavonoids, while phenolic acids exhibit low binding capacity. Hydrogen bonding and hydrophobic interactions were found to be dominant interactions involved in soybean protein-polyphenol binding. Cyanidin chloride exhibited the highest apparent binding constant (Ka), which was followed by quercetin, procyanidin, and rutin. Unlike others, procyanidin addition perturbed a red shift of SPI fluorescence, indicating a slight conformational change of SPI. (4) Conclusions: These results suggest that the pattern of SPI-polyphenol interaction is highly dependent on the detailed structure of polyphenols, which have important implications in uncovering the binding mechanism of SPI-polyphenol interaction.
(1) 背景：蛋白质 - 多酚相互作用因其对蛋白质和配体性质的影响而受到广泛研究。作为食品工业中的一种重要蛋白质材料，大豆分离蛋白（SPI）通过与多酚结合会发生有趣的变化。(2) 方法：在本研究中，建立了一种分子对接和虚拟筛选方法来评估SPI - 多酚相互作用。在虚拟筛选中使用了由33种常见食物来源多酚组成的化合物库。通过荧光测定法验证并比较了排名靠前的多酚（芦丁、原花青素、氯化花青素、槲皮素）的结合能力。(3) 结果：虚拟筛选中排名前五的多酚中有四种是黄酮类化合物，而酚酸的结合能力较低。发现氢键和疏水相互作用是大豆蛋白 - 多酚结合中的主要相互作用。氯化花青素表现出最高的表观结合常数（Ka），其次是槲皮素、原花青素和芦丁。与其他物质不同，添加原花青素会使SPI荧光发生红移，表明SPI有轻微的构象变化。(4) 结论：这些结果表明，SPI - 多酚相互作用模式高度依赖于多酚的详细结构，这对于揭示SPI - 多酚相互作用的结合机制具有重要意义。
