Ospina B, Núñez A, Fernández-Renart M
Departamento de Bioquímica, Facultad de Medicina, U.A.M., Madrid, Spain.
Mol Cell Biochem. 1992 Dec 2;118(1):49-60. doi: 10.1007/BF00249694.
A type II casein kinase has been purified from the soluble fraction of Dictyostelium discoideum vegetative cells. The enzyme has been purified 370 fold and behaves catalytically as casein kinase type II, in the sense that it utilizes GTP as well as ATP as phosphoryl donors, it is inhibited by low heparin concentrations and phosphorylates a specific peptide for CK II. It is a tetramer of 38 kDa-subunits with catalytic activity and ability to autophosphorylate in vitro. The comparison of this activity with the nuclear enzyme previously purified from the same organism indicates that both have the same molecular structure. Both enzymes have antigenic determinants in common with casein kinase II from bovine thymus, suggesting a high degree of conservation during evolution. Studies on the activity of this enzyme during early differentiation, and in the transition from quiescence to proliferation shows an increase in specific activity suggesting a crucial role for the enzyme in this organism.
一种II型酪蛋白激酶已从盘基网柄菌营养细胞的可溶性部分中纯化出来。该酶已被纯化了370倍，其催化行为表现为II型酪蛋白激酶，即它既利用GTP也利用ATP作为磷酰基供体，它受到低浓度肝素的抑制，并能磷酸化CK II的一种特定肽段。它是由38 kDa亚基组成的四聚体，具有催化活性和体外自磷酸化能力。将这种活性与先前从同一生物体中纯化的核酶进行比较表明，两者具有相同的分子结构。这两种酶都具有与牛胸腺酪蛋白激酶II共同的抗原决定簇，表明在进化过程中具有高度的保守性。对该酶在早期分化过程中以及从静止状态到增殖状态转变过程中的活性研究表明，比活性增加，表明该酶在这种生物体中起关键作用。
