Kinetic and structural characterization of a typical 2-cysteine peroxiredoxin from Leptospira interrogans exhibiting redox sensitivity

Abstract

Little is known about the mechanisms by which Leptospira interrogans, the causative agent of<br />leptospirosis,copes with oxidative stress at the time it establishes persistent infection with in its human host. Were port the molecular cloning of a gene encoding a 2-Cys peroxiredoxin (LinAhpC) from this bacterium. After bioinformatic analysis we found that LinAhpC contains the characteristic GGIG and YF motifs present in peroxiredoxins that are sensitive to overoxidation (mainly eukaryotic proteins).These motifs are absent in insensitive prokaryotic enzymes. Recombinant LinAhpC showed activity as a thioredoxin peroxidase with sensitivity to overoxidation by H2O2 (Chyp1% 30 mM at pH 7.0and 30 °C). So far, Anabaena 2-Cysperoxiredoxin, Helicobacter pylori AhpC, and LinAhpC are the only prokaryotic enzymes studied with these characteristics.The properties determined for LinAhpC suggest that the protein could be critical for the antioxidant defense capacity in L. interrogans.