Enomoto T, Tanuma S, Yamada M
Biochemistry. 1983 Mar 1;22(5):1134-8. doi: 10.1021/bi00274a022.
Isolated nuclei contained two active forms of DNA polymerase alpha (form I and form II). Form II was extracted from nuclei by KCl at concentrations lower than 0.18 M. Above 0.18 M selective extraction of form I was observed. The purified two active forms differed in chromatographic and electrophoretic behaviors, in their salt requirement for optimal activity, and in preference of template-primers, although both forms exhibited properties characteristic of DNA polymerase alpha such as sensitivity of N-ethylmaleimide, 1-beta-D-arabino-furanosylcytosine triphosphate, and aphidicolin. Marked difference between the two forms was preference of template-primer that form I was more active with poly(dT).(rA)10 than poly(dA).(dT)12 whereas form II exhibited higher activity with poly(dA).(dT)12 than poly(dT).(rA)10. Possible roles of two forms of DNA polymerase alpha in the processes of DNA replication will be discussed.
分离出的细胞核含有两种活性形式的DNA聚合酶α（形式I和形式II）。形式II可在浓度低于0.18 M的KCl作用下从细胞核中提取出来。高于0.18 M时，可观察到形式I的选择性提取。纯化后的两种活性形式在色谱和电泳行为、最佳活性所需的盐浓度以及对模板引物的偏好方面存在差异，尽管两种形式都表现出DNA聚合酶α的特性，如对N-乙基马来酰亚胺、1-β-D-阿拉伯呋喃糖基胞嘧啶三磷酸和阿非迪霉素敏感。两种形式之间的显著差异在于模板引物的偏好，形式I对聚（dT）·（rA）10的活性高于聚（dA）·（dT）12，而形式II对聚（dA）·（dT）12的活性高于聚（dT）·（rA）10。将讨论两种形式的DNA聚合酶α在DNA复制过程中的可能作用。
