Myricetin (MYR) is a bioactive secondary metabolite found in plants that is recognized for its nutraceutical value and is an essential constituent of various foods and beverages. It is reported to exhibit a plethora of activities, including antioxidant, antimicrobial, antidiabetic, anticancer, and anti-inflammatory. Alpha-2-macroglobulin (α2M) is a major plasma anti-proteinase that can inhibit proteinases of both human and non-human origin, regardless of their specificity and catalytic mechanism. Here, we explored the interaction of MYR-α2M using various biochemical and biophysical techniques. It was found that the interaction of MYR brings subtle change in its anti-proteolytic potential and thereby alters its structure and function, as can be seen from absorbance and fluorescence spectroscopy. UV spectroscopy of α2M in presence of MYR indicated the occurrence of hyperchromism, suggesting complex formation. Fluorescence spectroscopy reveals that MYR reduces the fluorescence intensity of native α2M with a shift in the wavelength maxima. At 318.15 K, MYR binds to α2M with a binding constant of 2.4 × 10³ M⁻¹, which indicates significant binding. The ΔG value was found to be − 7.56 kcal mol⁻¹ at 298.15 K, suggesting the interaction to be spontaneous and thermodynamically favorable. The secondary structure of α2M does not involve any major change as was confirmed by CD analysis. The molecular docking indicates that Asp-146, Ser-172, Glu-174, and Tyr-180 were the key residues involved in α2M-MYR complex formation. This study contributes to our understanding of the function and mechanism of protein and flavonoid binding by providing a molecular basis of the interaction between MYR and α2M.

杨梅素 (MYR) 是一种在植物中发现的具有生物活性的次级代谢产物，因其营养价值而闻名，是各种食品和饮料的重要成分。据报道，它表现出多种活性，包括抗氧化、抗菌、抗糖尿病、抗癌和抗炎。α-2-巨球蛋白 (α2M) 是一种主要的血浆抗蛋白酶，无论其特异性和催化机制如何，它都能抑制人类和非人类来源的蛋白酶。在这里，我们使用各种生化和生物物理技术探索了 MYR-α2M 的相互作用。研究发现，MYR 的相互作用会带来其抗蛋白水解潜能的细微变化，从而改变其结构和功能，这可以从吸光度和荧光光谱中看出。在 MYR 存在下 α2M 的紫外光谱表明发生了增色现象，表明形成了络合物。荧光光谱显示 MYR 降低了天然 α2M 的荧光强度，并改变了波长最大值。在 318.15 K 时，MYR 与 α2M 结合，结合常数为 2.4 × 10³  M ^-1，这表明显着的结合。发现在 298.15 K 时的Δ G值为 − 7.56 kcal mol ^-1，表明相互作用是自发的并且在热力学上是有利的。CD 分析证实，α2M 的二级结构没有发生任何重大变化。分子对接表明 Asp-146、Ser-172、Glu-174 和 Tyr-180 是参与 α2M-MYR 复合物形成的关键残基。这项研究通过提供 MYR 和 α2M 之间相互作用的分子基础，有助于我们理解蛋白质和类黄酮结合的功能和机制。