丹皮酚抑制蘑菇酪氨酸酶催化氧化L-Dopa的动力学

摘要

Aim To evaluate the effect of paeonol on the activity of tyrosinase and provide experimental evidence for the treatment of hyperpigmentation disorders. Methods Tyrosinase activity was estimated by measuring the oxidation rate of L-3,4-dihydroxyphenylalanine (L-Dopa). The inhibitory effects of paeonol on the activity of mushroom tyrosinase and Michaelis-Menten kinetics were deduced from the Lineweaver-Burk plots. Results The inhibitory concentration of paeonol leading to 50% enzyme Paeonol is a potential mixed inhibitor of mushroom tyrosinase. The mixed inhibition function may originate from its ability to form a Schiff base with a primary amino group and to chelate copper at the active site of tyrosinase.%目的研究丹皮酚对酪氨酸酶活性的影响,为色素增加性皮肤病的治疗提供实验依据.方法选用酪氨酸酶催化氧化3,4-二羟基苯丙氨酸(L-Dopa)速率法体外测定酪氨酸酶活性.应用Lineweaver-Burk曲线推导丹皮酚对酪氨酸酶活性的抑制效应及Michaelis-Menten动力学.结果导致酪氨酸酶活力下降50%的丹皮酚浓度为0.60mmol·L-1.丹皮酚对游离酶的抑制常数(KI)和对酶底物络合物的抑制常数(KIS)分别为0.084和0.12 mmol·L-1.结论丹皮酚是酪氨酸酶的混合型抑制剂,该抑制作用源于其能与酶中氨基结合生成席夫碱及能与活性中心的铜生成络合物.