ENZYME

ENZYME entry: EC 1.11.1.8

Accepted Name

Iodide peroxidase.

Alternative Name(s)

Iodinase.

Iodotyrosine deiodase.

Iodotyrosine deiodinase.

Thyroid peroxidase.

Thyroperoxidase.

TPO.

Reaction catalysed

2 iodide + H(2)O(2) + 2 H(+) <=> diiodine + 2 H(2)O
[Thyroglobulin]-L-tyrosine + iodide + H(2)O(2) <=> [thyroglobulin]-3-iodo-L-tyrosine + 2 H(2)O
[Thyroglobulin]-3-iodo-L-tyrosine + iodide + H(2)O(2) <=> [thyroglobulin]-3,5-diiodo-L-tyrosine + 2 H(2)O
2 [thyroglobulin]-3,5-diiodo-L-tyrosine + H(2)O(2) <=> [thyroglobulin]-L-thyroxine + [thyroglobulin]-aminoacrylate + 2 H(2)O
[Thyroglobulin]-3-iodo-L-tyrosine + [thyroglobulin]-3,5-diiodo-L-tyrosine + H(2)O(2) <=> [thyroglobulin]-3,5,3'-triiodo-L-thyronine + [thyroglobulin]-aminoacrylate + 2 H(2)O

Cofactor(s)

Heme.

Comment(s)

Thyroid peroxidase catalyzes the biosynthesis of the thyroid hormones L-thyroxine and triiodo-L-thyronine.
It catalyzes both the iodination of tyrosine residues in thyroglobulin (forming mono- and di-iodinated forms) and their coupling to form either L-thyroxine or triiodo-L-thyronine.

Cross-references

PROSITE

BRENDA

EC2PDB

ExplorEnz

PRIAM enzyme-specific profiles

KEGG Ligand Database for Enzyme Nomenclature