title: Kinetic and structural characterization of a typical two-cysteine peroxiredoxin from Leptospira interrogans exhibiting redox sensitivity.
abstract: Little is known about the mechanisms by which Leptospira interrogans, the causative agent of leptospirosis, copes with oxidative stress at the time it establishes persistent infection within its human host. We report 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 (Chyp 1% ~30 µM at pH 7.0 and 30°C). So far, Anabaena 2-Cys peroxiredoxin, 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.
authors.affiliation: Instituto de Agrobiotecnología del Litoral (CONICET), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, S3000ZAA Santa Fe, Argentina.
authors.forename: Diego G
authors.initials: DG
authors.lastname: Arias
authors.affiliation: Instituto de Agrobiotecnología del Litoral (CONICET), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, S3000ZAA Santa Fe, Argentina.
authors.forename: Anahí
authors.initials: A
authors.lastname: Reinoso
authors.affiliation: Instituto de Agrobiotecnología del Litoral (CONICET), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, S3000ZAA Santa Fe, Argentina.
authors.forename: Natalia
authors.initials: N
authors.lastname: Sasoni
authors.affiliation: Instituto de Agrobiotecnología del Litoral (CONICET), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, S3000ZAA Santa Fe, Argentina.
authors.forename: Matías D
authors.initials: MD
authors.lastname: Hartman
authors.affiliation: Instituto de Agrobiotecnología del Litoral (CONICET), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, S3000ZAA Santa Fe, Argentina.
authors.forename: Alberto A
authors.initials: AA
authors.lastname: Iglesias
authors.affiliation: Instituto de Agrobiotecnología del Litoral (CONICET), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, S3000ZAA Santa Fe, Argentina. Electronic address: sguerrer@fbcb.unl.edu.ar.
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Guerrero
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D004926:Escherichia coli; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007921:Leptospira interrogans / Q000201:enzymology*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D054464:Peroxiredoxins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny
chemical_list: D001426:Bacterial Proteins; D054464:Peroxiredoxins
keywords: Free radicals; Leptospira interrogans; Peroxide; Redox-sensitive peroxiredoxin; Thioredoxin system