【摘要】 槲皮素（Ｑｕｅｒｃｅｔｉｎ，Ｑｕｅ）为天然的黄酮类化合物，具有广泛的药理作用，酪蛋白激酶Ⅱ（ＣＫⅡ）在细胞的增殖和分化及血小板的活化过程中起重要作用．依次采用ＤＥＡＥ－纤维素和肝素－Ｓｅｐｈａｒｏｓｅ４Ｂ层析法部分纯化了大鼠肝ＣＫⅡ；发现槲皮素对ＣＫⅡ活性有强烈的抑制作用，其ＩＣ_５０为１２．２μｍｏｌ／Ｌ；Ｌｉｎｅｗｅａｖｅｒ－Ｂｕｒｋ双倒数作图表明：Ｑｕｅ对ＣＫⅡ的抑制作用与酪蛋白呈竞争性，而与ＡＴＰ呈非竞争性抑制．这可能是槲皮素抑制血小板聚集的又一机制，也可能与槲皮素抑制癌细胞ＤＮＡ合成有关．更多还原

【Abstract】 Quercetin,a naturally occurring flavonoid,has been proved to exert multiple pharmacological effects. Casein kinase Ⅱ （CK Ⅱ） had been implicated to play an important role in cell production and proliferation,and in the activation of platelet. In present study,CKⅡ was partially purified from rat livers by sequential DE52 and heparin-Sepharose chromatography and was characterized. It was found that quercetin strongly inhibited the activity of CK Ⅱ with IC₅₀ 12. 2 μmol·L￣（-1）.Lineweaer-Burk plot for the kinetic studies of quercetin effect on CK Ⅱ showed:inhibitory effect of quercetin on CKⅡ was competitive with casein and noncompetitive with ATP. The finding may explain the mechanism for quercetin to inhibit platelet aggregation,and also maybe related to the inhibition of the synthesis of DNA in tumor cells by quercetin.更多还原