来自小牛胸腺细胞核的一种不依赖环磷酸腺苷的蛋白激酶的纯化及性质
Purification and properties of a cyclic AMP-independent protein kinase from calf thymus nuclei.
作者信息
Kranias E G, Jungmann R A
出版信息
Biochim Biophys Acta. 1978 Feb 16;517(2):447-56. doi: 10.1016/0005-2787(78)90211-3.
A phosphoprotein kinase (ATP : protein phosphotransferase, EC 2.7.1.37) from calf thymus nuclei was purified by DEAE-cellulose chromatography, hydroxyapatite, and Sepharose 6B gel filtration. The enzyme is a cyclic AMP-independent protein kinase by the following criteria: (a) the protein kinase did not bind cyclic AMP; (b) no inhibition of activity was obtained with the heat-stable protein kinase inhibitor from rabbit skeletal muscle; (c) the regulatory subunit of cyclic AMP-dependent protein kinase had no effect on activity; and (d) no inhibition was obtained with antibody to cyclic AMP-dependent protein kinase. The nuclear cyclic AMP-independent protein kinase readily phosphorylated protamine on serine and to a lesser extent on threonine. Homologous nucleoplasmic RNA polymerase (EC 2.7.7.6) is a better substrate than arginine-rich histone, phosvitin or casein. Physical characteristics of the enzyme are described.
通过二乙氨基乙基纤维素色谱法、羟基磷灰石和琼脂糖6B凝胶过滤法，从小牛胸腺细胞核中纯化出一种磷蛋白激酶（ATP：蛋白质磷酸转移酶，EC 2.7.1.37）。根据以下标准，该酶是一种不依赖环磷酸腺苷的蛋白激酶：（a）该蛋白激酶不结合环磷酸腺苷；（b）兔骨骼肌中热稳定的蛋白激酶抑制剂对其活性无抑制作用；（c）依赖环磷酸腺苷的蛋白激酶的调节亚基对其活性无影响；（d）依赖环磷酸腺苷的蛋白激酶抗体对其无抑制作用。这种细胞核内不依赖环磷酸腺苷的蛋白激酶能轻易地使鱼精蛋白的丝氨酸磷酸化，苏氨酸磷酸化程度较低。同源核质RNA聚合酶（EC 2.7.7.6）比富含精氨酸的组蛋白、卵黄高磷蛋白或酪蛋白更适合作为底物。文中描述了该酶的物理特性。
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