Ascorbate peroxidase

Ascorbate peroxidases (or APX) are enzymes that detoxify peroxides such as hydrogen peroxide using ascorbate as a substrate. The reaction they catalyse is the transfer of electrons from ascorbate to a peroxide, producing dehydroascorbate and water as products.[1]

Ascorbate + Hydrogen peroxide → Dehydroascorbate + Water

C6H8O6 + H2O2 → C6H6O6 + 2 H2O

APX is an integral component of the glutathione-ascorbate cycle.[2] These enzymes are commonly hemoproteins and the haem cofactor is the site of the oxidation-reduction reaction shown above.[3]

References

  1. ↑ Raven EL (2000). "Peroxidase-catalyzed oxidation of ascorbate. Structural, spectroscopic and mechanistic correlations in ascorbate peroxidase". Subcell. Biochem. Subcellular Biochemistry. 35: 317–49. doi:10.1007/0-306-46828-X_10. ISBN 0-306-46399-7. PMID 11192727.
  2. ↑ Noctor G, Foyer CH (Jun 1998). "ASCORBATE AND GLUTATHIONE: Keeping Active Oxygen Under Control". Annu Rev Plant Physiol Plant Mol Biol. 49: 249–279. doi:10.1146/annurev.arplant.49.1.249. PMID 15012235.
  3. ↑ Raven EL, Lad L, Sharp KH, Mewies M, Moody PC (2004). "Defining substrate specificity and catalytic mechanism in ascorbate peroxidase". Biochem. Soc. Symp. (71): 27–38. PMID 15777010.

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