The role of glutathione peroxidases in trypanosomatids.
Reactive oxygen species are the unwanted by-products of aerobic metabolism. To protect cells against their potentially lethal effects a series of pathways have evolved that are collectively called the oxidative defence system. In most eukaryotes, catalases and selenium-dependent glutathione peroxidases form the front line of defence against hydroperoxide-mediated damage. However, these activities are lacking in members of the Trypanosomatidae family of protozoan parasites. Instead these organisms contain several enzyme-mediated pathways for removal of hydroperoxides that are centred upon the unusual thiol trypanothione. Here we discuss the biochemical properties of one group of these enzymes, the non-selenium glutathione-dependent peroxidases, and outline the roles that they play in protecting the parasite against hydroperoxides associated with biological membranes.
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
Shane R
SR
Wilkinson
John M
JM
Kelly
D000595:Amino Acid Sequence; D000818:Animals; D005979:Glutathione Peroxidase / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D014345:Trypanosoma / Q000201:enzymology* / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000201:enzymology
D005979:Glutathione Peroxidase