Plasmodium falciparum: properties of an alpha-like DNA polymerase, the key enzyme in DNA synthesis

Exp Parasitol. 1990 Jul;71(1):21-6. doi: 10.1016/0014-4894(90)90004-v.

Abstract

An alpha-like DNA polymerase has been identified and characterized in the extracts from the malarial parasite Plasmodium falciparum. The enzyme is sensitive to the specific inhibitors of alpha-DNA polymerase, N-ethylmaleimide and aphidicolin, and is cell-cycle specific. High activity has been found in the schizont, is lower in trophozoites, and has only negligible activity in the ring form. The enzyme has a molecular weight of about Mr 100,000-103,000 estimated by detecting activity in SDS-polyacrylamide electrophoresis and by Bio-Gel filtration. Another active band of a molecular Mr 68,000 was detected by SDS electrophoresis when the enzyme was stored for 2 months at -20 degrees C. The catalytic activity of parasite enzyme was optimal between pH 8 and pH 9. The apparent Michaelis constant for dTTP was 4.3 microM.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology
  • Aphidicolin
  • Cell Cycle
  • Chromatography, Gel
  • DNA / biosynthesis*
  • DNA Polymerase II / analysis*
  • DNA Polymerase II / antagonists & inhibitors
  • DNA Polymerase II / immunology
  • Diterpenes / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Ethylmaleimide / pharmacology
  • Hydrogen-Ion Concentration
  • Molecular Weight
  • Plasmodium falciparum / enzymology*
  • Plasmodium falciparum / genetics

Substances

  • Antibodies, Monoclonal
  • Diterpenes
  • Aphidicolin
  • DNA
  • DNA Polymerase II
  • Ethylmaleimide