ABSTRACT
Kinetoplastids are primitive eukaryotes that can be found either as free-living organisms or as obligate parasites in a diverse range of invertebrates or vertebrates. The oxidation of thiols by one- or two-electron processes leads to the formation of thiyl radicals and sulfenic acids, respectively. Generation of a sulfenic acid in trypanothione will rapidly be solved by the formation of an intramolecular disulfide. Isolated trypanothione is able to protect DNA damage by scavenging radiation-induced radicals only in the presence of trypanothione reductase and NADPH to maintain the reduced state. This higher protective effect compared to Glutathione was attributed to accumulation of trypanothione in the proximity of the DNA due to the spermidine moiety. The synthesis of ascorbic acid in kinetoplastids occurs in the glycosome, a subcellular compartment exclusive to this class. The synthesis is completed by an FMN-dependent galactonolactone oxidase located in this compartment.
