Oxidoreductases;
Acting on a peroxide as acceptor;
Peroxidases

1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol:hydrogen-peroxide oxidoreductase

(1) 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol + H2O2 = 3,4-dimethoxybenzaldehyde + 2-methoxyphenol + glycolaldehyde + H2O [RN:R11501];
(2) 2 (3,4-dimethoxyphenyl)methanol + H2O2 = 2 (3,4-dimethoxyphenyl)methanol radical + 2 H2O [RN:R11502]

R11501 R11502;
(other) R04461

1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol [CPD:C21419];
H2O2 [CPD:C00027];
(3,4-dimethoxyphenyl)methanol [CPD:C21420]

A hemoprotein, involved in the oxidative breakdown of lignin by white-rot basidiomycete fungi. The reaction involves an initial oxidation of the heme iron by hydrogen peroxide, forming compound I (FeIV=O radical cation) at the active site. A single one-electron reduction of compound I by an electron derived from a substrate molecule yields compound II (FeIV=O non-radical cation), followed by a second one-electron transfer that returns the enzyme to the ferric oxidation state. The electron transfer events convert the substrate molecule into a transient cation radical intermediate that fragments spontaneously. The enzyme can act on a wide range of aromatic compounds, including methoxybenzenes and nonphenolic beta-O-4 linked arylglycerol beta-aryl ethers, but cannot act directly on the lignin molecule, which is too large to fit into the active site. However larger lignin molecules can be degraded in the presence of veratryl alcohol. It has been suggested that the free radical that is formed when the enzyme acts on veratryl alcohol can diffuse into the lignified cell wall, where it oxidizes lignin and other organic substrates. In the presence of high concentration of hydrogen peroxide and lack of substrate, the enzyme forms a catalytically inactive form (compound III). This form can be rescued by interaction with two molecules of the free radical products. In the case of veratryl alcohol, such an interaction yields two molecules of veratryl aldehyde.

EC 1.11.1.14 created 1992, modified 2006, modified 2011, modified 2016

1  [PMID:2982828]

Kersten PJ, Tien M, Kalyanaraman B, Kirk TK.

The ligninase of Phanerochaete chrysosporium generates cation radicals from methoxybenzenes.

J. Biol. Chem. 260 (1985) 2609-12.

2  [PMID:3080953]

Paszczynski A, Huynh VB, Crawford R.

Comparison of ligninase-I and peroxidase-M2 from the white-rot fungus Phanerochaete chrysosporium.

Arch. Biochem. Biophys. 244 (1986) 750-65.

3

Harvey, P.J., Schoemaker, H.E. and Palmer, J.M.

Veratryl alcohol as a mediator and the role of radical cations in lignin biodegradation by Phanerochaete chrysosporium.

FEBS Lett. 195 (1986) 242-246.

4  [PMID:2162833]

Wariishi H, Marquez L, Dunford HB, Gold MH.

Lignin peroxidase compounds II and III. Spectral and kinetic characterization of reactions with peroxides.

J. Biol. Chem. 265 (1990) 11137-42.

5  [PMID:2328240]

Cai DY, Tien M.

Characterization of the oxycomplex of lignin peroxidases from Phanerochaete chrysosporium: equilibrium and kinetics studies.

Biochemistry. 29 (1990) 2085-91.

6  [PMID:8527462]

Khindaria A, Yamazaki I, Aust SD

Veratryl alcohol oxidation by lignin peroxidase.

Biochemistry. 34 (1995) 16860-9.

7  [PMID:8639588]

Khindaria A, Yamazaki I, Aust SD

Stabilization of the veratryl alcohol cation radical by lignin peroxidase.

Biochemistry. 35 (1996) 6418-24.

8  [PMID:9369491]

Khindaria A, Nie G, Aust SD

Detection and characterization of the lignin peroxidase compound II-veratryl alcohol cation radical complex.

Biochemistry. 36 (1997) 14181-5.

9  [PMID:9790672]

Doyle WA, Blodig W, Veitch NC, Piontek K, Smith AT.

Two substrate interaction sites in lignin peroxidase revealed by site-directed mutagenesis.

Biochemistry. 37 (1998) 15097-105.

10 [PMID:25649492]

Pollegioni L, Tonin F, Rosini E

Lignin-degrading enzymes.

FEBS. J. 282 (2015) 1190-213.