Murakami-Murofushi K, Mano Y
Biochim Biophys Acta. 1977 Mar 18;475(2):254-66. doi: 10.1016/0005-2787(77)90016-8.
A protein factor, SF I, which stimulated DNA polymerase activity severalfold was purified from nuclei of sea urchin embryos by phase separation, ammonium sulfate fractionation, DNA-cellulose, CM-cellulose and hydroxyapatitecolumn chromatography and gel filtration. The molecular weight of SF I was about 220 000, the S20,W value was about 8.5 and the isoelectric point was determined to be pH 5.1. In the presence of SF I,V of the DNA-polymerizing reaction was increased and Km values for the substrates of this reaction were not changed. Addition of polyamines increased the rate of stimulation. ATP which was required for stimulation could be substituted by other ribonucleoside triphosphates. SF I, nuclear DNA polymerase and ATP seemed to form an active complex, and in the complex, ATP was found to have been converted to AMP and inorganic pyrophosphate.
一种能使DNA聚合酶活性提高数倍的蛋白质因子SF I，通过相分离、硫酸铵分级分离、DNA纤维素、CM纤维素和羟基磷灰石柱色谱及凝胶过滤，从海胆胚胎细胞核中纯化得到。SF I的分子量约为220000，S20,W值约为8.5，等电点测定为pH 5.1。在SF I存在的情况下，DNA聚合反应的V增加，该反应底物的Km值不变。多胺的添加提高了刺激速率。刺激所需的ATP可被其他核糖核苷三磷酸替代。SF I、核DNA聚合酶和ATP似乎形成了一个活性复合物，并且在该复合物中，发现ATP已转化为AMP和无机焦磷酸。
