Reaction: glutathione + ROOH = glutathione disulfide + H2O + ROH
For diagram of reaction, click here and for mechanism, click here
Other name(s): PRDX6 (gene name); prx3 (gene name)
Systematic name: glutathione:hydroperoxide oxidoreductase
Comments: Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins. They can be divided into three classes: typical 2-Cys, atypical 2-Cys and 1-Cys peroxiredoxins [1]. The peroxidase reaction comprises two steps centred around a redox-active cysteine called the peroxidatic cysteine. All three peroxiredoxin classes have the first step in common, in which the peroxidatic cysteine attacks the peroxide substrate and is oxidized to S-hydroxycysteine (a sulfenic acid) (see mechanism). The second step of the peroxidase reaction, the regeneration of cysteine from S-hydroxycysteine, distinguishes the three peroxiredoxin classes. For typical 2-Cys Prxs, in the second step, the peroxidatic S-hydroxycysteine from one subunit is attacked by the ‘resolving’ cysteine located in the C-terminus of the second subunit, to form an intersubunit disulfide bond, which is then reduced by one of several cell-specific thiol-containing reductants completing the catalytic cycle. In the atypical 2-Cys Prxs, both the peroxidatic cysteine and its resolving cysteine are in the same polypeptide, so their reaction forms an intrachain disulfide bond. The 1-Cys Prxs conserve only the peroxidatic cysteine, so its regeneration involves direct interaction with a reductant molecule. Glutathione-dependent peroxiredoxins have been reported from bacteria and animals, and appear to be 1-Cys enzymes. The mechanism for the mammalian PRDX6 enzyme involves heterodimerization of the enzyme with π-glutathione S-transferase, followed by glutathionylation of the oxidized cysteine residue. Subsequent dissociation of the heterodimer yields glutathionylated peroxiredoxin, which is restored to the active form via spontaneous reduction by a second glutathione molecule.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Wood, Z.A., Schröder, E., Harris, J.R. and Poole, L.B. Structure, mechanism and regulation of peroxiredoxins. Trends Biochem. Sci. 28 (2003) 32-40. [PMID: 12517450]
2. Pauwels, F., Vergauwen, B., Vanrobaeys, F., Devreese, B. and Van Beeumen, J.J. Purification and characterization of a chimeric enzyme from Haemophilus influenzae Rd that exhibits glutathione-dependent peroxidase activity. J. Biol. Chem. 278 (2003) 16658-16666. [PMID: 12606554]
3. Manevich, Y., Feinstein, S.I. and Fisher, A.B. Activation of the antioxidant enzyme 1-CYS peroxiredoxin requires glutathionylation mediated by heterodimerization with π GST. Proc. Natl. Acad. Sci. USA 101 (2004) 3780-3785. [PMID: 15004285]
4. Greetham, D. and Grant, C.M. Antioxidant activity of the yeast mitochondrial one-Cys peroxiredoxin is dependent on thioredoxin reductase and glutathione in vivo. Mol. Cell Biol. 29 (2009) 3229-3240. [PMID: 19332553]
5. Lim, J.G., Bang, Y.J. and Choi, S.H. Characterization of the Vibrio vulnificus 1-Cys peroxiredoxin Prx3 and regulation of its expression by the Fe-S cluster regulator IscR in response to oxidative stress and iron starvation. J. Biol. Chem. 289 (2014) 36263-36274. [PMID: 25398878]