柚皮素对α-葡萄糖苷酶的抑制作用及其机制

为研究柚皮素对α-葡萄糖苷酶的抑制作用，本文采用酶动力学、荧光光谱和分子对接等方法研究了柚皮素对α-葡萄糖苷酶的抑制效果、抑制作用类型及其抑制作用的分子机制。柚皮素对α-葡萄糖苷酶的IC₅₀为0.174 mmol/L，显著低于阿卡波糖的0.721 mmol/L，为非竞争型抑制剂，K_i值为0.114 mmol/L；柚皮素和α-葡萄糖苷酶的结合导致了酶分子的内在荧光静态猝灭，猝灭常数为0.1598×104 L/mol，结合位点数n为1。分子对接结果显示，在氢键、离子键、疏水作用、π-π T型堆积、静电作用五种作用力的驱动下，柚皮素结合于α-葡萄糖苷酶分子的一个疏水口袋中，结合能为?7.6 kJ/mol。本文研究结果表明，柚皮素是一种较好的食源性α-葡萄糖苷酶抑制剂，在辅助治疗糖尿病功能食品中具有良好的应用前景。

Inhibitory Effect of Naringin on α-Glucosidase and Its Mechanism

To investigate the inhibitory activity and mechanism of naringin on α-glucosidase, the inhibition effect, type, and molecular mechanism of naringin on α-glucosidase were investigated by integrative analysis of enzyme kinetics, fluorescence spectroscopy and molecular docking simulation. The results showed that IC₅₀ of naringin against α-glucosidase was 0.174 mmol/L, which was significantly lower than that of acarbose (IC₅₀=0.721 mmol/L). The inhibition type was non-competitive inhibition with a K_i of 0.114 mmol/L. The binding of naringin and α-glucosidase led to the internal fluorescence quenching of the enzyme molecule. Furhter analysis indicated that the quenching constant was 0.1598×104 L/mol, and there was only one binding site. The molecular docking results showed that naringin was bound to a hydrophobic pocket of α-glucoside enzyme by the driving force of hydrogen bond, ionic bond, hydrophobic action, π-π-T stacking, and electrostatic action, with a binding energy of ?7.6 kJ/mol. The results indicated that naringin was a good food-borne α-glucosidase inhibitor, and therefore had a good application prospect in the adjuvant treatment of diabetes functional food.