大豆黄酮对重组人蛋白激酶CK2全酶的抑制作用及其动力学分析

Inhibitory effect of daidzein on recombinant holoenzyme of human protein kinase CK2 and its kinetic analysis

目的 :体外观察大豆黄酮对重组人蛋白激酶 CK2的抑制效果及酶动力学分析以确定其抑制作用类型。方法 :利用基因工程技术进行克隆、表达和纯化 ,获得重组人 CK2的 α'及 β亚基在体外等摩尔混合构成 CK2全酶 ,并测定大豆黄酮对酶的抑制作用及采用 IC50 结果的回归方程分析其动力学。结果 :大豆黄酮能显著抑制重组人蛋白激酶 CK2的活性 (IC50 =2 .38μmol/ L ) ,抑制作用明显强于已知的 CK2抑制剂 5,6-二氯 - 1 -β- D-呋喃核糖苯并咪唑 (DRB)和 N- (2 -氨乙基 ) - 5-氯萘 - 1 -硫胺 (A3)。酶动力学分析表明 ,大豆黄酮与 ATP(Ki=3.0 2 μmol/ L)及酪蛋白 (Ki=2 .2 2 μmol/ L)均呈混合型抑制 CK2的活性。结论 :大豆黄酮是一种较强的体外蛋白激酶 CK2的抑制剂。

Objective: To investigate the inhibitory effect of daidzein on recombinant holoenzyme of human protein kinase CK2 and analyze its kinetics. Methods: α', and β subunits of human protein kinase CK2 were cloned, expressed and purified, and then mixed at equal molar to constitute CK2 holoenzyme. The inhibitory effect of daidzein on recombinant holoenzyme and its kinetics were determined according to IC 50 . Results: Daidzein obviously inhibited CK2 holoenzyme activity (IC 50 = 2.38 μmol/L), and its inhibitory effect was superior to that of the known CK2 inhibitors such as 5, 6-dichloro-1-β-D-ribofuranosyl benzimidazole (DRB) and N-2-aminoethyl-5-chloronaphthalene-1-sulfonamide (A3). The inhibitory effects of both daidzein and ATP (K i=3.02 μmol/L) or casein (K i=2.22 μmol/L) on the holoenzyme appeared in mixed types. Conclusion: Daidzein is an effective inhibitor of protein kinase CK2 in vitro.