Overview for MACiE Entry M0239
EC Number: 18.104.22.168 (A member of the Oxidoreductases, Acting on a peroxide as acceptor, Peroxidases)
Enzyme Name: peroxidase
Biological Species: Armoracia rusticana (Horseradish)
Catalytic Chain UniprotKB Accession Codes:
Representative PDB Code: 7atj - RECOMBINANT HORSERADISH PEROXIDASE C1A COMPLEX WITH CYANIDEAND FERULIC ACID (Resolution = 1.47 Å).
Catalytic CATH Codes:
"Other" CATH Codes:
Display structure information
Overall Comment: Horseradish peroxidase oxidises a broad range of phenolic derivatives. As such no specific substrate has been used in this entry.
View similar reactions
Stepwise Description of the Reaction
|Step 1||His42 deprotonates hydrogen peroxide. The resulting anion coordinates to the Fe(III) centre of Hem350, displacing water and forming Cpd0.|
|Step 2||The O-O bond of Cpd0 undergoes heterolytic cleavage and the resulting hydroxide is protonated by His42. The porphryin ring and Fe(III) donate an electron each to the oxygen bound to the metal.|
|Step 3||His42 deprotonates water, which then deprotonates the phenolic derivative substrate. The phenolate transfers an electron to the porphyrin ring, forming a phenolic radical and Cpd1.|
|Step 4||The oxygen of Cpd1 is protonated by water, which is in turn protonated by His42.|
|Step 5||The porphyrin ring transfers an electron to the Fe(IV) centre to give an isomer of Cpd1.|
|Step 6||Arg38 transfers a proton to the oxygen of Cpd1.|
|Step 7||Upon binding of the second phenol derivative, Arg38 deprotonates Cpd2.|
|Step 8||His42 deprotonates water, which then deprotonates the phenolic derivative substrate. The phenolate transfers an electron to the porphyrin ring radical, forming a phenolic radical.|
|Step 9||The metal-bound hydroxide is protonated by water, which is in turn protonated by His42.|
View similar reactions (composite manual annotation)
Catalytic Residues Involved
||Location of Function
Metal Cofactors for M0239
- E. Derat et al. (2006), J. Am. Chem. Soc., 128, 13940-13949. An efficient proton-coupled electron-transfer process during oxidation of ferulic acid by horseradish peroxidase: coming full cycle.
- E. Derat et al. (2006), J. Phys. Chem. B, 110, 10526-10533. The Poulos-Kraut mechanism of Compound I formation in horseradish peroxidase: a QM/MM study.
- A. Henriksen et al. (1999), J. Biol. Chem., 274, 35005-35011. The structures of the horseradish peroxidase C-ferulic acid complex and the ternary complex with cyanide suggest how peroxidases oxidize small phenolic substrates.
- K. Meno et al. (2002), Acta Crystallogr. D Biol. Crystallogr., 58, 1803-1812. Structural analysis of the two horseradish peroxidase catalytic residue variants H42E and R38S/H42E: implications for the catalytic cycle.
- M. Gajhede (2000), Biochem. Soc. Trans., 29, 91-98. Plant peroxidases: substrate complexes with mechanistic implications.
Homologue information for M0239 (7atj)
MACiE Homologues (within the PDB)
MACiE Homologues (within UniprotKB/SwissProt)
Links to this entry in other databases