结合分子对接技术研究牦牛乳干酪苦味肽RK7和KQ7的α-淀粉酶抑制活性

以牦牛乳干酪苦味肽RPKHPIK(RK7)和KVLPVPQ(KQ7)为研究对象，通过生物信息学方法，使用ExPASy-ProtParam、Innovagen和PepDraw等工具计算RK7和KQ7的理化性质，利用分子对接技术揭示抑制α-淀粉酶的作用机制，结合体外实验测定α-淀粉酶抑制活性。研究表明：RK7和KQ7的分子质量分别为875.07 Da和779.98 Da，疏水性分别为42.86%和71.42%；分子对接显示α-淀粉酶中的His305、Glu233、Trp59和Trp58与RK7和KQ7的结合起重要作用，并且Asp197、Glu233和Asp300是影响α-淀粉酶活性的关键氨基酸；体外活性验证发现，RK7和KQ7 α-淀粉酶的IC₅₀分别为0.45 mg/mL和0.86 mg/mL。本研究通过生物信息学方法结合体外活性实验，高效快速获得牦牛乳源α-淀粉酶抑制肽，并通过分子对接技术探究分子间的作用机制，为α-淀粉酶抑制肽的研究提供新思路。

Using Molecular Docking to Investigate the Alpha-amylase Inhibitory Activity of Bitter Peptides RK7 and KQ7 Derived from Yak Cheese

In this study, the physicochemical properties of two bitter peptides derived from yak cheese, RPKHPIK (RK7) and KVLPVPQ (KQ7) were calculated by using online bioinformatics tools such as ExPASy-ProtParam, Innovagen, and Pep-Draw. Molecular docking was used to elucidate the mechanism of the inhibitory effect of the two peptides on α-amylase and their α-amylase inhibitory activity was determined. The results showed that the molecular masses of RK7 and KQ7 were 875.07 and 779.98 Da, and their hydrophobicity were 42.86% and 71.42%, respectively. Molecular docking showed that His305, Glu233, Trp59 and Trp58 in α-amylase played an important role in binding to RK7 and KQ7. Furthermore, Asp197, Glu233 and Asp300 were the key amino acids for the activity of α-amylase. The half maximal inhibitory concentration (IC50) of RK7 and KQ7 against α-amylase were 0.45 and 0.86 mg/mL, respectively. The findings of this study provide new evidence for the study of α-amylase inhibitory peptides.