Accepted Name |
glutathione-dependent peroxiredoxin
|
Reaction catalysed |
a hydroperoxide + 2 glutathione = an alcohol + glutathione disulfide + H2O |
Comment(s) |
- 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 1.11.1.15.
|
Cross-references |
BRENDA | 1.11.1.27 |
EC2PDB | 1.11.1.27 |
ExplorEnz | 1.11.1.27 |
PRIAM enzyme-specific profiles | 1.11.1.27 |
KEGG Ligand Database for Enzyme Nomenclature | 1.11.1.27 |
IUBMB Enzyme Nomenclature | 1.11.1.27 |
IntEnz | 1.11.1.27 |
MEDLINE | Find literature relating to 1.11.1.27 |
MetaCyc | 1.11.1.27 |
Rhea expert-curated reactions | 1.11.1.27 |
UniProtKB/Swiss-Prot |
P00450, CERU_HUMAN | Q61147, CERU_MOUSE | P13635, CERU_RAT |
Q9XT27, CERU_SHEEP | O77834, PRDX6_BOVIN | Q5ZJF4, PRDX6_CHICK |
P30041, PRDX6_HUMAN | Q2PFL9, PRDX6_MACFA | P86215, PRDX6_MESAU |
O08709, PRDX6_MOUSE | Q9TSX9, PRDX6_PIG | Q5R7E0, PRDX6_PONAB |
O35244, PRDX6_RAT | P34227, PRX1_YEAST | P44758, PRX5_HAEIN |
O69777, PRX5_RHIET | Q53212, PRX5_SINFN | P73728, PRX5_SYNY3 |
|
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