| EC |
1.97.1.10 |
| Accepted name: |
thyroxine 5′-deiodinase |
| Reaction: |
3,5,3′-triiodo-L-thyronine + iodide + A + H+ = L-thyroxine + AH2 |
| Other name(s): |
diiodothyronine 5′-deiodinase [ambiguous]; iodothyronine 5′-deiodinase; iodothyronine outer ring monodeiodinase; type I iodothyronine deiodinase; type II iodothyronine deiodinase; thyroxine 5-deiodinase [misleading]; L-thyroxine iodohydrolase (reducing) |
| Systematic name: |
acceptor:3,5,3′-triiodo-L-thyronine oxidoreductase (iodinating) |
| Comments: |
The enzyme activity has only been demonstrated in the direction of 5′-deiodination, which renders the thyroid hormone more active. The enzyme consists of type I and type II enzymes, both containing selenocysteine, but with different kinetics. For the type I enzyme the first reaction is a reductive deiodination converting the -Se-H group of the enzyme into an -Se-I group; the reductant then reconverts this into -Se-H, releasing iodide. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, METACYC, CAS registry number: 70712-46-8 |
| References: |
| 1. |
Chopra, I.J. and Teco, G.N.C. Characteristics of inner ring (3 or 5) monodeiodination of 3,5-diiodothyronine in rat liver: evidence suggesting marked similarities of inner and outer ring deiodinases for iodothyronines. Endocrinology 110 (1982) 89–97. [PMID: 7053997] |
| 2. |
Goswani, A., Leonard, J.L. and Rosenberg, I.N. Inhibition by coumadin anticoagulants of enzymatic outer ring monodeiodination of iodothyronines. Biochem. Biophys. Res. Commun. 104 (1982) 1231–1238. [PMID: 6176242] |
| 3. |
Smallridge, R.C., Burman, K.D., Ward, K.E., Wartofsky, L., Dimond, R.C., Wright, F.D. and Lathan, K.R. 3′,5′-Diiodothyronine to 3′-monoiodothyronine conversion in the fed and fasted rat: enzyme characteristics and evidence for two distinct 5′-deiodinases. Endocrinology 108 (1981) 2336–2345. [PMID: 7227308] |
| 4. |
Körhle, J. Iodothyronine deiodinases. Methods Enzymol. 347 (2002) 125–167. [PMID: 11898402] |
|
| [EC 1.97.1.10 created 1984 as EC 3.8.1.4, transferred 2003 to EC 1.97.1.10] |
| |
|
| |
|
Printable version