DIFFERENT EFFECTS OF VANADIUM IONS ON SOME DNA METABOLIZING ENZYMES
The effects of vanadium on some enzymes involved in DNA metabolism were investigated in vitro. Vanadate (V) ions competitively inhibit calf thymus terminal deoxynucleotidyl transferase with K-i = 2.5 muM. A binding of vanadium to the enzyme with no change of the amount of the Zn constituent of the protein was found at concentrations of vanadate causing inhibition. The catalytic activity of mammalian DNA polymerase varies as was also inhibited by vanadate ions at an 1-50 of 60 muM, while the bacterial (E. coli) DNA polymerase I was affected to the same extent only when the concentration of vanadate was raised to about the 0.5 mM. In contrast to the inhibitory effects caused by vanadium on the nucleotidyl transferases, concentrations of pentavalent vanadium ions of the order of 10 muM increase 2.4-fold the hydrolytic activity of dexoyribonuclease I from bovine pancreas. These findings suggest that vanadium can interact with enzymes involved in nucleic acid metabolism.
Bibliographic Reference: JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH, VOL. 12 (1983), PP. 737-748
Record Number: 1989122080300 / Last updated on: 1987-01-01
Available languages: en