Solubilization and characterization of particulate form of DNA polymerase from adult rat liver nuclei

Abstract

DNA polymerase was solubilized from adult liver chromatin-membrane complex. The activity of this solubilized enzyme was 20–30 times higher than that of the partially purified cytoplasmic DNA polymerase. The solubilized nuclear particulate enzyme differed from the cytoplasmic enzyme in properties such as template preference, salt effect and pH optimum. ATP stimulated only the cytoplasmic enzyme, but EDTA and spermidine, stimulated the solubilized nuclear particulate enzyme but not the cytoplasmic enzyme. On sucrose density gradient centrifugation the cytoplasmic DNA polymerase sedimented around 9 S and the solubilized nuclear enzyme sedimented around 3–4 S.