Martos C, Plana M, Guasch M D, Itarte E
Biochem J. 1985 Jan 15;225(2):321-6. doi: 10.1042/bj2250321.
Starvation, diabetes and insulin did not alter the concentration of casein kinases in rat liver cytosol. However, the Km for casein of casein kinase 2 from diabetic rats was about 2-fold lower than that from control animals. Administration of insulin to control rats did not alter this parameter, but increased the Km for casein of casein kinase 2 in diabetic rats. Starvation did not affect the kinetic constants of casein kinases. The effect of diabetes on casein kinase 2 persisted after partial purification of the enzyme by glycerol-density-gradient centrifugation and affected also its activity on other protein substrates such as phosvitin, high-mobility-group protein 14 and glycogen synthase. The results indicate that rat liver cytosol casein kinase 2 is under physiological control.
饥饿、糖尿病和胰岛素均未改变大鼠肝脏胞质溶胶中酪蛋白激酶的浓度。然而,糖尿病大鼠的酪蛋白激酶2对酪蛋白的米氏常数(Km)比对照动物的约低2倍。给对照大鼠注射胰岛素不会改变该参数,但会增加糖尿病大鼠中酪蛋白激酶2对酪蛋白的Km。饥饿不影响酪蛋白激酶的动力学常数。通过甘油密度梯度离心对该酶进行部分纯化后,糖尿病对酪蛋白激酶2的影响依然存在,并且该影响也作用于其对其他蛋白质底物(如卵黄高磷蛋白、高迁移率族蛋白14和糖原合酶)的活性。结果表明大鼠肝脏胞质溶胶中的酪蛋白激酶2受生理调控。