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.
Wilkinson
Shane R
SR
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
Kelly
John M
JM
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