The trypanothione system.
Trypanosomes and Leishmania, the causative agents of severe tropical diseases, employ 2-Cys-peroxiredoxins together with cysteine-homologues of glutathione peroxidases and ascorbate-dependent peroxidases for the detoxification of hydroperoxides. All three types of peroxidases gain their reducing equivalents from the parasite-specific dithiol trypanothione [bis(glutathionyl)spermidine]. Based on their primary structure and cellular localization, the trypanosomatid 2-Cys-peroxiredoxins are subdivided into two families that occur in the mitochondrion and cytosol of the parasites. In Trypanosoma brucei, the cytosolic 2-Cys-peroxiredoxin, as well as the glutathione peroxidase-type enzyme, is essential for cell viability. Despite overlapping substrate specificities and subcellular localizations, the two types of peroxidases can obviously not substitute for each other which suggests distinct cell-physiological roles.
Krauth-Siegel
Luise R
LR
Biochemie-Zentrum der Universität Heidelberg, Germany.
Comini
Marcelo A
MA
Schlecker
Tanja
T
D000818:Animals; D060387:Ascorbate Peroxidases; D003593:Cytoplasm / Q000201:enzymology; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D007891:Leishmania / Q000201:enzymology; D010544:Peroxidases / Q000378:metabolism*; D010545:Peroxides / Q000378:metabolism; D054464:Peroxiredoxins / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism*; D013095:Spermidine / Q000031:analogs & derivatives* / Q000378:metabolism; D013379:Substrate Specificity; D014346:Trypanosoma brucei brucei / Q000201:enzymology*
D010545:Peroxides; D015800:Protozoan Proteins; C044809:trypanothione; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D054464:Peroxiredoxins; D005979:Glutathione Peroxidase; D005978:Glutathione; D013095:Spermidine