柚皮素对α-葡萄糖苷酶的抑制作用及其机制

Inhibitory Effect of Naringin onα-Glucosidase and Its Mechanism

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IC_(50)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0.1598×10^(4)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-πT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。

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 IC_(50) of naringin againstα-glucosidase was 0.174 mmol/L,which was significantly lower than that of acarbose(IC_(50)=0.721 mmol/L).The inhibition type was non-competitive inhibition with a K_(i) of 0.114 mmol/L.The binding of naringin andα-glucosidase led to the internal fluorescence quenching of the enzyme molecule.Furhter analysis indicated that the quenching constant was 0.1598×10^(4)L/mol,and there was only one binding site.The molecular docking results showed that naringin was bound to a hydrophobic pocket ofα-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 foodborneα-glucosidase inhibitor,and therefore had a good application prospect in the adjuvant treatment of diabetes functional food.