Mitochondrial protein synthesis in Plasmodium falciparum

Mol Biochem Parasitol. 1986 Jan;18(1):37-43. doi: 10.1016/0166-6851(86)90048-4.

Abstract

Protein synthesis in intact Plasmodium falciparum was 333 times more sensitive to cycloheximide than to chloramphenicol. The 50% inhibitory concentration (IC50) of cycloheximide in a 27-h assay in vitro was 6 X 10(-7) M but no constant cycloheximide-insensitive fraction of total protein synthesis was observed at concentrations of this inhibitor between 10(-7) and 10(-2) M. 0.24% of total protein synthesis occurred in the presence of 10(-3) M cycloheximide but the chloramphenicol sensitivity of this fraction was similar to that of overall protein synthesis (IC50 2 X 10(-4) M). The major fraction of protein synthesis by P. falciparum, therefore, is assumed to be cytoplasmic and to occur on 80S ribosomes. Cycloheximide-insensitive, chloramphenicol-sensitive (70S ribosomal) protein synthesis being undetectable by the methods employed, mitochondrial protein synthesis in P. falciparum is presumed to constitute a considerably smaller fraction of the total protein synthetic capacity than observed in other lower eukaryotes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chloramphenicol / pharmacology
  • Cycloheximide / pharmacology
  • Cytoplasm / metabolism
  • Isoleucine / metabolism
  • Mitochondria / metabolism*
  • Plasmodium falciparum / metabolism*
  • Plasmodium falciparum / ultrastructure
  • Protein Biosynthesis*
  • Ribosomes / metabolism

Substances

  • Isoleucine
  • Chloramphenicol
  • Cycloheximide