tailieunhanh - Báo cáo khoa học: Peroxiredoxins as cellular guardians in Sulfolobus solfataricus – characterization of Bcp1, Bcp3 and Bcp4

Peroxiredoxins are ubiquitous enzymes that are part of the oxidative stress defense system. In the present study, we identified three peroxiredoxins [bacterioferritin comigratory protein (Bcp)1, Bcp3 and Bcp4] in the genome of the aerobic hyperthermophilic archaeon Sulfolobus solfataricus. | ỊFEBS Journal Peroxiredoxins as cellular guardians in Sulfolobus solfataricus - characterization of Bcp1 Bcp3 and Bcp4 Danila Limauro1 Emilia Pedone2 Ilaria Galdi1 and Simonetta Bartolucci1 1 Dipartimento di Biologia Strutturale e Funzionale Universita di Napoli Federico II Complesso Universitario Monte S. Angelo Naples Italy 2 Istituto di Biostrutture e Bioimmagini CNR Naples Italy Keywords antioxidant archaea disulfide oxidoreductase oxidative stress thiol-peroxidase Correspondence Simonetta Bartolucci Dipartimento di Biologia Strutturale e Funzionale Complesso Universitario di Monte S. Angelo Universita di Napoli Federico II Via Cinthia 80126 Naples Italy Fax 39 081679053 Tel 39 081679052 E-mail bartoluc@ Received 20 December 2007 revised 22 February 2008 accepted 27 February 2008 doi Peroxiredoxins are ubiquitous enzymes that are part of the oxidative stress defense system. In the present study we identified three peroxiredoxins bacterioferritin comigratory protein Bcp 1 Bcp3 and Bcp4 in the genome of the aerobic hyperthermophilic archaeon Sulfolobus solfataricus. Based on the cysteine residues conserved in the deduced aminoacidic sequence Bcp1 and Bcp4 can be classified as 2-Cys peroxiredoxins and Bcp3 as a 1-Cys peroxiredoxin. A comparative study of the recombinant Bcps produced in Escherichia coli showed that these enzymes protect DNA plasmid from oxidative damage and remove both H2O2 and tert-butyl hydroperoxide although at different efficiencies. We observed that all of them were particularly thermostable and that peak enzymatic activity fell within the range of the growth temperature of S. solfataricus. Furthermore we discovered an alternative Bcp reduction system whose composition differs from that of the peroxiredoxin reduction system previously characterized in the aerobic hyperthermophilic archaeon Aeropyrum pernix. Whereas the latter uses the thioredoxin thioredoxin reductase NADPH system this alternative Bcp