Abstract：
The substantial nutritional content and diversified biological activity of plant-based nutraceuticals are due to polyphenolic chemicals. These chemicals are important and well-studied plant secondary metabolites. Their protein interactions are extensively studied. This relationship is crucial for the logical development of functional food and for enhancing the availability and usefulness of polyphenols. This study highlights the influence of protein types and polyphenols on the interaction, where the chemical bindings predominantly consist of hydrophobic interactions and hydrogen bonds. The interaction between polyphenolic compounds (PCs) and digestive enzymes concerning their inhibitory activity has not been fully studied. Therefore, we have examined the interaction of four digestive enzymes (α-amylase, pepsin, trypsin, and α-chymotrypsin) with four PCs (curcumin, diosmin, morin, and 2\',3\',4\'-trihydroxychalcone) through in silico and in vitro approaches. In vitro plate assays, enzyme kinetics, spectroscopic assays, molecular docking, and simulations were performed. We observed all these PCs have significant docking scores and preferable interaction with the active site of the digestive enzymes, resulting in the reduction of enzyme activity. The enzyme-substrate binding mechanism was determined using the Lineweaver Burk plot, indicating that the inhibition occurred competitively. Among four PCs diosmin and morin has the highest interaction energy over digestive enzymes with IC50 value of 1.13 ± 0.0047 and 1.086 ± 0.0131 μM. Kinetic studies show that selected PCs inhibited pepsin, trypsin, and chymotrypsin competitively and inhibited amylase in a non-competitive manner, especially by 2\',3\',4\'-trihydroxychalcone. This study offers insights into the mechanisms by which the selected PCs inhibit the enzymes and has the potential to enhance the application of curcumin, diosmin, morin, and 2\',3\',4\'-trihydroxychalcone as natural inhibitors of digestive enzymes.
摘要：
基于植物的营养食品的大量营养成分和多样化的生物活性是由于多酚化学品。这些化学物质是重要且研究良好的植物次生代谢产物。它们的蛋白质相互作用被广泛研究。这种关系对于功能性膳食的逻辑发展以及增强多酚的可用性和有用性至关重要。这项研究强调了蛋白质类型和多酚对相互作用的影响，其中化学键主要由疏水相互作用和氢键组成。PC与消化酶之间有关其抑制活性的相互作用尚未得到充分研究。因此,我们研究了四种消化酶(胃蛋白酶，α-淀粉酶,胰蛋白酶,和α-胰凝乳蛋白酶）与四个PC（姜黄素，Diosmin,Morin,和2\'，3\',4'-三羟基查耳酮)通过计算机模拟和体外方法。体外平板测定，酶动力学，光谱测定，分子对接,并进行了模拟。我们观察到所有这些PC都具有显着的对接得分和与消化酶活性位点的优选相互作用，导致酶活性降低。使用LineweaverBurk图确定了酶-底物结合机制，表明抑制是竞争性发生的。在四个PC中，狄奥司明和莫林与消化酶的相互作用能最高，IC50值为1.13±0.0047和1.086±0.0131μM。动力学研究表明，选定的PC抑制胃蛋白酶，胰蛋白酶,和胰凝乳蛋白酶竞争性地抑制淀粉酶，尤其是2\'，3\',4\'-三羟基查耳酮。这项研究提供了对所选PC抑制酶的机制的见解，并有可能增强姜黄素的应用，Diosmin,Morin,和2\'，3\',4\'-三羟基查耳酮作为消化酶的天然抑制剂。
