enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. ...

, a lignin peroxidase () is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. ...

that

catalyzes Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

the

chemical reaction A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breakin ...

:1,2-bis(3,4-dimethoxyphenyl)propane-1,3-diol + H₂O₂

\rightleftharpoons

3,4-dimethoxybenzaldehyde + 1-(3,4-dimethoxyphenyl)ethane-1,2-diol + H₂O Thus, the two substrates of this enzyme are 1,2-bis(3,4-dimethoxyphenyl)propane-1,3-diol and H₂O₂, whereas its 3

products Product may refer to: Business * Product (business), an item that serves as a solution to a specific consumer problem. * Product (project management), a deliverable or set of deliverables that contribute to a business solution Mathematics * Prod ...

are

3,4-dimethoxybenzaldehyde Veratraldehyde (3,4-dimethoxybenzaldehyde) is an organic compound that is widely used as a flavorant and odorant. The compound is structurally related to benzaldehyde. This compound is popular commercially because of its pleasant woody fragrance ...

, 1-(3,4-dimethoxyphenyl)ethane-1,2-diol, and H₂O. This enzyme belongs to the family of

oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ut ...

s, specifically those acting on a peroxide as acceptor (peroxidases) and can be included in the broad category of

ligninase Lignin-modifying enzymes (LMEs) are various types of enzymes produced by fungi and bacteria that catalyze the breakdown of lignin, a biopolymer commonly found in the cell walls of plants. The terms ligninases and lignases are older names for the sa ...

s. The

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

of this enzyme class is 1,2-bis(3,4-dimethoxyphenyl)propane-1,3-diol:hydrogen-peroxide oxidoreductase. Other names in common use include diarylpropane oxygenase, ligninase I, diarylpropane peroxidase, LiP, diarylpropane:oxygen,hydrogen-peroxide oxidoreductase (C-C-bond-cleaving). It employs one cofactor,

heme Heme, or haem (pronounced / hi:m/ ), is a precursor to hemoglobin, which is necessary to bind oxygen in the bloodstream. Heme is biosynthesized in both the bone marrow and the liver. In biochemical terms, heme is a coordination complex "consist ...

Background

Lignin Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity a ...

is highly resistant to biodegradation and only higher fungi and some bacteria are capable of degrading the polymer via an oxidative process. This process has been studied extensively in the past twenty years, but the mechanism has not yet been fully elucidated. Lignin is found to be degraded by enzyme lignin peroxidases produced by some fungi like ''Phanerochaete chrysosporium''. The mechanism by which lignin peroxidase (LiP) interacts with the lignin polymer involves

veratrole alcohol Veratrole alcohol (veratryl alcohol) is an organic compound related to veratrole and also to benzyl alcohol. It can be obtained by reduction of veratraldehyde. Veratrole alcohol is the raw material for the synthesis of cyclotriveratrylene which ...

, which is a secondary metabolite of white rot fungi that acts as a cofactor for the enzyme.

Structural studies

As of late 2007, 3

structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such a ...

have been solved for this class of enzymes, with PDB accession codes , , and .

References

* * * * * * * * * * * * {{Portal bar, Biology, border=no EC 1.11.1 Heme enzymes Enzymes of known structure