Action of Partially Thiolated Polynucleotides on the DNA Polymerase a from Regenerating Rat Liver1

sanger, and amino acid transfer of the macromolecules. The inhibitory effects of partially Ihiobated polynucleotides on nucleic acid polymarases from Micrococcus !ysodeikti cus (i6), RNA humor viruses (7, 8), and cultured Bunkitt lymphoma calls (21) have been described. Recent studies revealed that the partially thiolated polynucleohides can en tar tumor cells and are transported into the nuclear fraction (12, i8). Results of initial animal experiments and some preliminary chemotherapeutic results in human leukemia have been reported (9). Preliminary data have been presented (8) on the inhibition by partially thiolated polynucleotides of a DNA polymamase isolated from regenerating rat liven nuclei by the early method of Mantsavinos (i4) and believed to have come spondad to the low-molecular-weight “DNA pobymemaseI―, i.e., the fJenzyme (6). To gain some information relevant to structure-activity relationships and mode of action, the at facts of various types of modified and unmodified nucleic acids on the purified DNA polymenase a from regenerating rat liver nuclei (I 1) were investigated , and in i case the sensitivity of this enzyme ho inhibition by a partially hhiolated polynucleotida was compared to that of the purified DNA polymerase 13from the normal rat livernuclear fraction.