PEROXIDOXINS - A NEW ANTIOXIDANT FAMILY

Peroxidoxins are a recently described family of antioxidants. They hav e an ancient origin, being present in organisms as primitive as the ar chaea, and they appear to be ubiquitous in living cells. Here, Sharon McGonigle, John Dalton and Eric lames review the present understanding of the functions and mechanism of action of these enzymes and suggest that these antioxidants may represent the 'missing link' in the metab olism of reactive oxygen species by some protozoan and helminth parasi tes. Also, by performing sequence comparisons of homologues entered in the public databases, they have classified the parasite peroxidoxins as 1-cys or 2-cys enzymes. The discovery of these antioxidants may cha nge our understanding of how reactive oxygen species, of parasite or h ost origin, are managed by parasites.