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ENZYME entry: EC

Accepted Name
glutathione-dependent peroxiredoxin
Reaction catalysed
a hydroperoxide + 2 glutathione <=> an alcohol + glutathione disulfide + H2O
  • 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.
  • The peroxidase reaction comprises two steps centered 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).
  • 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 pi-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.
  • Formerly EC
PRIAM enzyme-specific profiles1.11.1.27
KEGG Ligand Database for Enzyme Nomenclature1.11.1.27
IUBMB Enzyme Nomenclature1.11.1.27
MEDLINEFind literature relating to
Rhea expert-curated reactions1.11.1.27
P34227, PRX1_YEASTP44758, PRX5_HAEINO69777, PRX5_RHIET
Q53212, PRX5_SINFNP73728, PRX5_SYNY3

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