Differential susceptibilities of DNA polymerases-alpha and -beta to polyanions

Nucleic Acids Res. 1978 Sep;5(9):3427-38. doi: 10.1093/nar/5.9.3427.


The effects of various polyanions including synthetic polynucleotides on DNApolymerases-alpha and -beta from blastulae of the sea urchin Hemicentrotus pulcherrimus and HeLa cells were studied. Only DNA polymerase-alpha was inhibited by polyanions, such as polyvinyl sufate, dextran sulfate, heparin, poly(G), poly(I), poly(U) and poly(ADP-Rib). Of the various polynucleotides tested, poly(G) and poly(I) were the strongest inhibitors. Kinetic studies showed that the Ki value for poly(G) was 0.3 microgram/ml and that poly(G) had 20-fold higher affinity than activated DNA for the template-primer site of DNA polymerase-alpha. Poly(U) and poly(ADP-Rib) were also inhibitory, but they were one hundredth as inhibitory as poly(G) or poly(I). Poly(A), poly(C), poly(A).poly(U) AND POLY(I).poly(C) were not inhibitory to DNA polymerase-alpha. In contrast, DNA olymerase-beta was not affected at all by these polyanions under the same conditions.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Anions / pharmacology
  • Binding, Competitive
  • Dose-Response Relationship, Drug
  • HeLa Cells
  • Kinetics
  • Nucleic Acid Synthesis Inhibitors*
  • Poly Adenosine Diphosphate Ribose / pharmacology
  • Polyribonucleotides / pharmacology
  • Sea Urchins / enzymology


  • Anions
  • Nucleic Acid Synthesis Inhibitors
  • Polyribonucleotides
  • Poly Adenosine Diphosphate Ribose