Differential inhibition of eukaryotic DNA polymerases by halenaquinol sulfate, a p-hydroquinone sulfate obtained from a marine sponge

Abstract Halenaquinol sulfate, a p -hydroquinone sulfate obtained from a marine sponge, inhibited the activity of eukaryotic DNA polymerases in varying degrees; the K i values for DNA polymerases α, β, δ and e were 1.3, 80, 17.5 and 2.0 νM, respectively, whereas it was less effective against E. coli DNA polymerase I. The inhibition occurred competitively with each of dATP and dTTP, but non-competitively with dCTP, dGTP and the template DNA. Thus, halenaquinol sulfate is demonstrated to be a potential inhibitor of DNA polymerases α and e, and be a useful tool for analysing the DNTP binding sites of DNA polymerases.