Hofmann F, Gensheimer H P, Göbel C
FEBS Lett. 1983 Dec 12;164(2):350-4. doi: 10.1016/0014-5793(83)80315-9.
cGMP-Dependent protein kinase contains, per subunit, 2 binding sites for cGMP. The apparent KD values for site 1 and 2 were 12 and 55 nM. The analogues 8-benzyl-amino-cAMP and N2-monobutyryl-cGMP bind preferentially to site 1 and 2, respectively. Both analogues stimulate autophosphorylation of the enzyme at concentrations at which only half of the phosphotransferase activity of the enzyme is expressed. Complete expression of the phosphotransferase activity requires a high concentration of each analogue and is accompanied by inhibition of the autophosphorylation reactions. It is concluded that occupancy of site 1 or 2 stimulates autophosphorylation while occupancy of both sites prevents autophosphorylation.
依赖环磷酸鸟苷（cGMP）的蛋白激酶每个亚基含有2个cGMP结合位点。位点1和位点2的表观解离常数（KD）值分别为12 nM和55 nM。类似物8-苄基氨基-环磷酸腺苷（cAMP）和N2-单丁酰-cGMP分别优先结合位点1和位点2。在仅表达该酶一半磷酸转移酶活性的浓度下，这两种类似物均刺激该酶的自身磷酸化。磷酸转移酶活性的完全表达需要高浓度的每种类似物，并伴随着自身磷酸化反应的抑制。得出的结论是，位点1或位点2的占据刺激自身磷酸化，而两个位点都被占据则阻止自身磷酸化。
