目的:观察7种黄酮类化合物时重组人蛋白激酶CK2全酶活性的影响并进行结构效应关系的分析.方法:将利用基因工程技术获得的重组人CK2 α'及β亚基在体外等摩尔混合构成CK2全酶.通过测定药物作用后转移到CK2底物上的[γ-32P]ATP的32P的放射性活度,探讨黄酮类化合物对重组人CK2全酶活性的抑制作用,并采用半数效量概率单位法计算其IC50值.结果:杨梅黄酮、槲皮素、桑色素、毛地黄黄酮、莰非醇、芹菜苷配基和白杨黄素能明显抑制重组人CK2全酶活性,其IC50值分别是1.18,0.51,16.16,0.86,1.88,1.72和13.63 umol/L;其中杨梅黄酮、槲皮素、毛地黄黄酮、莰非醇和芹菜苷配基的作用效果均强于目前已知的CK2抑制剂DRB和A3;而桑色素和白杨黄素的作用效果接近于DRB.结构效应关系分析表明,C6,C3'和C4'上的-OH可能是黄酮类CK2抑制剂发挥抑制作用的药效基团;而在C3上去除1个.OH对其抑制效果基本没有影响;此外,C2'和C5'上的-OH可减弱黄酮类化合物对CK2的抑制作用.结论:黄酮类化合物对体外蛋白激酶CK2的抑制效果可能取决于其羟基的位置.%Objective To observe the effect of 7 flavonoids on recombinant human protein kinase CK2 holoenzyme activity and investigate their structure-activity relationship. Methods Recombinant hu-man protein kinase CK2 α' and β subunits were mixed at equal molar ratio to reconstitute CK2 holoen-zyme. The CK2 activity was assayed by detecting incorporation of 32p of [γ-32P] ATP into the substrate for the inhibitory effect by flavonoids and calculation of IC50 was performed according to probability unit (PROBIT) method. Results Myricetin, quercetin, morin, luteolin, kaempferol, apigenin, and chrysin were shown to obviously inhibit recombinant CK2 holoenzyme activity in a concentration-dependent man-ner with IC50 values of 1.18, 0.51, 16.16, 0.86, 1.88, 1.72, and 13.63 umol/L, respectively. Myricetin, quercetin, luteolin, kaempferol, and apigenin were more effective than DRB and A3, which were known as CK2 inhibitors in vitro. Whereas morin and chrysin displayed a similar effect to DRB. Structure-activity study indicated that the major structural requirements for the potent inhibition of CK2 by these flavonoids were hydroxyl group at position 6, 3' and 4'. Different from these requirements, absence of a hydroxyl group at position 3 did not modify their inhibitory potency, while addition of hydroxyl groups at positions 2' or 5' was detrimental to the inhibitory effect on CK2. Conclusion The inhibitory effect of flavonoid on protein kinase CK2 in vitro may be determined by the position of their hydroxyl groups.
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