IntEnz

EC 1.11.1.8 - Iodide peroxidase

IntEnz Enzyme Nomenclature
EC 1.11.1.8

Names

Reactions

• (1) 2 iodide + H2O2 + 2 H+ = diiodine + 2 H2O
• (2) thyroglobulin-L-tyrosine + iodide + H2O2 = thyroglobulin-3-iodo-L-tyrosine + 2 H2O
• (3) thyroglobulin-3-iodo-L-tyrosine + iodide + H2O2 = thyroglobulin-3,5-diiodo-L-tyrosine + 2 H2O
• (4) 2 thyroglobulin-3,5-diiodo-L-tyrosine + H2O2 = thyroglobulin-L-thyroxine + thyroglobulin-aminoacrylate + 2 H2O
• (5) thyroglobulin-3-iodo-L-tyrosine + thyroglobulin-3,5-diiodo-L-tyrosine + H2O2 = thyroglobulin-3,5,3'-triiodo-L-thyronine + thyroglobulin-aminoacrylate + 2 H2O

Cofactor

• heme

Comments:

Thyroid peroxidase catalyses the biosynthesis of the thyroid hormones L-thyroxine and triiodo-L-thyronine. It catalyses 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.

Links to other databases

References

1. Cunningham, B. A., Kirkwood, S.
   Enzyme systems concerned with the synthesis of monoiodotyrosine. III. Ion requirements of the soluble system.
   J. Biol. Chem. 236 : 485-489 (1961). [PMID: 13718859]
2. Hosoya, T., Kondo, Y., Ui, N.
   Peroxidase activity in thyroid gland and partial purification of the enzyme.
   J. Biochem. 52 : 180-189 (1962). [PMID: 13964156]
3. Coval, M. L., Taurog, A.
   Purification and iodinating activity of hog thyroid peroxidase.
   J. Biol. Chem. 242 : 5510-5523 (1967). [PMID: 12325367]
4. Gavaret, J. M., Cahnmann, H. J., Nunez, J.
   Thyroid hormone synthesis in thyroglobulin. The mechanism of the coupling reaction.
   J. Biol. Chem. 256 : 9167-9173 (1981). [PMID: 7021557]
5. Ohtaki, S., Nakagawa, H., Nakamura, M., Yamazaki, I.
   One- and two-electron oxidations of tyrosine, monoiodotyrosine, and diiodotyrosine catalyzed by hog thyroid peroxidase.
   J. Biol. Chem. 257 : 13398-13403 (1982). [PMID: 7142155]
6. Magnusson, R. P., Taurog, A., Dorris, M. L.
   Mechanism of iodide-dependent catalatic activity of thyroid peroxidase and lactoperoxidase.
   J. Biol. Chem. 259 : 197-205 (1984). [PMID: 6706930]
7. Virion, A., Courtin, F., Deme, D., Michot, J. L., Kaniewski, J., Pommier, J.
   Spectral characteristics and catalytic properties of thyroid peroxidase-H2O2 compounds in the iodination and coupling reactions.
   Arch. Biochem. Biophys. 242 : 41-47 (1985). [PMID: 2996435]
8. Rawitch, A. B., Pollock, G., Yang, S. X., Taurog, A.
   Thyroid peroxidase glycosylation: the location and nature of the N-linked oligosaccharide units in porcine thyroid peroxidase.
   Arch. Biochem. Biophys. 297 : 321-327 (1992). [PMID: 1497352]
9. Sun, W., Dunford, H. B.
   Kinetics and mechanism of the peroxidase-catalyzed iodination of tyrosine.
   Biochemistry 32 : 1324-1331 (1993). [PMID: 8448141]
10. Taurog, A., Dorris, M. L., Doerge, D. R.
    Mechanism of simultaneous iodination and coupling catalyzed by thyroid peroxidase.
    Arch. Biochem. Biophys. 330 : 24-32 (1996). [PMID: 8651700]
11. Ruf, J., Carayon, P.
    Structural and functional aspects of thyroid peroxidase.
    Arch. Biochem. Biophys. 445 : 269-277 (2006). [PMID: 16098474]

[EC 1.11.1.8 created 1961, modified 2012]