Lim JC, et al. (2008) Irreversible Oxidation of the Active-site Cysteine of Peroxiredoxin to Cysteine Sulfonic Acid for Enhanced Molecular Chaperone Activity. J Biol Chem 283(43):28873-80
Abstract: Thiol (-SH) of the active cysteine residue in peroxiredoxin is known to be reversibly hyperoxidized to cysteine sulfinic acid (-SO2H), which can be reduced back to thiol by sulphiredoxin/sestrin. However, hyperoxidized peroxiredoxin of an irreversible nature has not been reported yet. Using an antibody developed against the sulfonylated (-SO3H) yeast peroxiredoxin (Tsa1p) active site peptide (AFTFVCPTEI), we observed the increase in the immunoblot intensity in proportion to the H2O2 concentrations treated to the yeast cells. We identified two species of hyperoxidized Tsa1p: one can be reduced back (reversible) and the other cannot be reduced back (irreversible) by the aid of sulphiredoxin. The irreversibly hyperoxidized Tsa1p was identified as containing the active site cysteine sulfonic acid (Tsa1p-SO3H) by mass spectrometry. Tsa1p-SO3H was not an autoxidation product of Tsa1p-SO2H and was maintained in yeast cells even after two doubling cycles. Tsa1p-SO3H self-assembled into a ring-shaped multimeric form was shown by electron microscopy. While the Tsa1p-SO3H multimer lost its peroxidase activity, it gained ~4-folds higher chaperone activity than Tsa1p-SH. In this study, we identify an irreversibly hyperoxidized peroxiredoxin, Tsa1p-SO3H, with enhanced molecular chaperone activity, and suggest Tsa1p-SO3H is a marker of cumulative oxidative stress in cells.
|Status: Published||Type: Journal Article||PubMed ID: 18725414|
Topics addressed in this paper
- To go to the Locus page for a gene, click on the gene name.
|Protein Physical Properties|
|Techniques and Reagents|