ENZYME

ENZYME entry: EC 1.11.1.10

Accepted Name

Chloride peroxidase.

Alternative Name(s)

Chloroperoxidase.

CPO.

Vanadium haloperoxidase.

Reaction catalysed

RH + Cl(-) + H(2)O(2) <=> RCl + 2 H(2)O

Cofactor(s)

Heme.

Comment(s)

Brings about the chlorination of a range of organic molecules, forming stable C-Cl bonds.
Also oxidizes bromide and iodide.
Enzymes of this type are either heme-thiolate proteins, or contain vanadate.
A secreted enzyme produced by the ascomycetous fungus Caldariomyces fumago (Leptoxyphium fumago) is an example of the heme-thiolate type.
It catalyzes the production of hypochlorous acid by transferring one oxygen atom from H(2)O(2) to chloride.
At a separate site it catalyzes the chlorination of activated aliphatic and aromatic substrates, via HClO and derived chlorine species.
In the absence of halides, it shows peroxidase (e.g. phenol oxidation) and peroxygenase activities.
The latter inserts oxygen from H(2)O(2) into, for example, styrene (side chain epoxidation) and toluene (benzylic hydroxylation), however, these activities are less pronounced than its activity with halides.
Has little activity with non-activated substrates such as aromatic rings, ethers or saturated alkanes.
The chlorinating peroxidase produced by ascomycetous fungi (e.g. Curvularia inaequalis) is an example of a vanadium chloroperoxidase, and is related to bromide peroxidase (EC 1.11.1.18).
It contains vanadate and oxidizes chloride, bromide and iodide into hypohalous acids.
In the absence of halides, it peroxygenates organic sulfides and oxidizes ABTS (2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)) but no phenols.

Cross-references

PROSITE

BRENDA

EC2PDB

ExplorEnz

PRIAM enzyme-specific profiles

KEGG Ligand Database for Enzyme Nomenclature