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Determining the Molecular Basis for Differential Hyperoxidation Sensitivity in Peroxiredoxin 1 & 2
Author(s) -
Bolduc Jesalyn,
ReiszHaines Julie,
Nelson Kimberly,
Furdui Cristina,
Lowther W Todd
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.895.10
Subject(s) - peroxiredoxin , gene isoform , oxidative stress , reactive oxygen species , chemistry , biochemistry , cysteine , cytoplasm , microbiology and biotechnology , biology , enzyme , peroxidase , gene
Oxidative stress, a cellular condition in which the levels of reactive oxygen species (ROS; e.g., hydrogen peroxide, H 2 O 2 ) are too high, causes damage to macromolecules and has been linked to several pathologies including cancer, diabetes, Alzheimer's disease, and cardiovascular disease. One way cells maintain homeostatic levels of ROS is to produce a variety of peroxiredoxins (Prxs). Prxs are redox‐sensitive, antioxidant enzymes that remove H 2 O 2 . However, Prxs can be inactivated by hyperoxidation of the active site cysteine (Cys‐S P H) residue to Cys sulfinic acid (Cys‐S P O 2 H). Interestingly, Prx1 is more resistant to hyperoxidation than Prx2, despite the fact that they share 77% sequence identity and are both located in the cytoplasm. The molecular basis for this variability between isoforms in their susceptibilities to inactivation is unknown, but it is important to study since Prx inactivation is implicated in oxidative stress‐associated diseases. We hypothesize that residues unique to hPrx1 cause it to be more resistant to hyperoxidation. We have successfully cloned, expressed, and purified a library of chimeras that target groups of the most dissimilar residues between the two isoforms. We have determined the hyperoxidation sensitivity of the wild type hPrx1 and hPrx2 as well as each chimera using a variety of kinetic assays. By analyzing the changes these chimeras cause in hyperoxidation sensitivity, we have identified two novel, resistance‐conferring motifs. Sources of research support: AHA MAA: 14PRE19970007, NIGMS/NIH: R01 GM072866