Molecular characterization of a 2-Cys peroxiredoxin from the human malaria parasite Plasmodium falciparum

Mol Biochem Parasitol. 2001 Aug;116(1):73-9. doi: 10.1016/s0166-6851(01)00308-5.

Abstract

We have identified the 2-Cys peroxiredoxin (PfPrx-1) from the human malaria parasite Plasmodium falciparum. The PfPrx-1 showed the highest identity at amino acid level to the type II Prx among the currently known six subfamilies of mammalian Prx. The sequence identity between the PfPrx-1 and the previously reported 1-Cys Prx of P. falciparum (PfPrx-2), which corresponded to mammalian type VI Prx, was 25%. This suggests that the parasite possesses two Prx subfamilies. The PfPrx-1 showed significant sequence similarities with those of 2-Cys peroxiredoxins of plants in the BLASTX search. This may reflect the consequences of a genetic transfer from an algal endosymbiont to the parasite nucleus during evolution. The recombinant PfPrx-1 protein (rPfPrx-1) was expressed as a histidine fusion protein in Escherichia coli and purified with Ni chromatography. The rPfPrx-1 existed as dimers under non-reducing conditions and dissociated into monomers in the presence of dithiothreitol. The PfPrx-1 protein also exists as a dimer in the parasites themselves. The reduction of the oxidized enzyme by the donation of electrons from E. coli thioredoxin (Trx)/Trx reductase system was demonstrated in its reaction with H(2)O(2), using the rPfPrx-1 protein. These results suggested that the PfPrx-1 can act as a terminal peroxidase of the parasite Trx system. An elevated expression of the PfPrx-1 protein seen in the trophozoite, the stage with active metabolism, suggests an association of the parasite Trx system with its intracellular redox control.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antioxidants
  • Cloning, Molecular
  • Molecular Sequence Data
  • Peroxidases / genetics*
  • Peroxiredoxin VI
  • Peroxiredoxins
  • Plasmodium falciparum / enzymology
  • Plasmodium falciparum / genetics*
  • Plasmodium falciparum / pathogenicity
  • Protozoan Proteins / genetics
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid

Substances

  • Antioxidants
  • Protozoan Proteins
  • Peroxidases
  • Peroxiredoxin VI
  • Peroxiredoxins

Associated data

  • GENBANK/AB037568