Iurkiv V A, Petukhov S P, Bulargina T V, Severin E S
Biull Eksp Biol Med. 1981 Oct;91(10):429-32.
cAMP-dependent and casein proteinkinase were found in cytosol of the rabbit small intestine mucosa. cAMP-dependent proteinkinase of cytosol is represented by two forms of types I and II. The activity of enzymes of types I and II constitutes 10 and 90%, respectively. Casein proteinkinase is represented by a single form. The catalytic subunit of cAMP-dependent proteinkinase of type II was isolated in a homogenous state. The catalytic subunit phosphorylates histones H1, H2a, H2b and protamine and to a far less degree histones H3, H4 and casein (H2b greater than H1 greater than H2a greater than protamine much greater than H3 greater than casein). The Km value for histone H1 is equal to 65 mkM, and that for Mg-ATP 12 mkM. Chloromethylpyrophosphonate and adenosine p-fluorosulfobenzoate were studied as affine modifiers of the active center of the catalytic subunit from the small intestine mucosa. It was shown that only adenosine p-fluorosulfonate is an irreversible inhibitor of the catalytic subunit.
在兔小肠黏膜的胞质溶胶中发现了环磷酸腺苷（cAMP）依赖性蛋白激酶和酪蛋白激酶。胞质溶胶中的cAMP依赖性蛋白激酶有I型和II型两种形式。I型和II型酶的活性分别占10%和90%。酪蛋白激酶只有一种形式。II型cAMP依赖性蛋白激酶的催化亚基被分离出来呈均一状态。该催化亚基可使组蛋白H1、H2a、H2b和鱼精蛋白磷酸化，而对组蛋白H3、H4和酪蛋白的磷酸化程度要低得多（H2b＞H1＞H2a＞鱼精蛋白＞＞H3＞酪蛋白）。组蛋白H1的米氏常数（Km）值等于65微摩尔，镁 - 三磷酸腺苷（Mg - ATP）的Km值为12微摩尔。研究了氯甲基焦磷酸酯和对氟磺酰苯甲酸腺苷作为小肠黏膜催化亚基活性中心的亲和修饰剂。结果表明，只有对氟磺酰苯甲酸腺苷是催化亚基的不可逆抑制剂。
