iodotyrosine deiodinase activity

Definition

Target type: molecularfunction

Catalyzes the reaction: 2 iodide + L-tyrosine + 2 NADP+ = 3,5-diiodo-L-tyrosine + H+ + 2 NADPH. Note that this activity has only been demonstrated in the direction of 3-deiodination. 3-bromo-L-tyrosine and 3-chloro-L-tyrosine can also be used as substrates. [PMID:15289438, PMID:18434651, PMID:25395621, PMID:27643701, RHEA:32479]

Iodotyrosine deiodinase activity is a crucial step in the thyroid hormone synthesis pathway. It is catalyzed by enzymes known as deiodinases, specifically type 1 and type 2. These enzymes remove iodine from the tyrosine ring of iodotyrosines, which are precursors to thyroid hormones. This deiodination process is essential for generating the active forms of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), from their inactive precursors. The reaction involves the reduction of the iodine atom on the tyrosine ring, resulting in the release of iodide and the formation of a deiodinated tyrosine derivative. The deiodinases utilize selenium-containing selenocysteine residues in their active sites to facilitate this reaction. These enzymes play a vital role in regulating thyroid hormone levels and maintaining thyroid homeostasis. They are also involved in the metabolism of thyroid hormones, converting T4 to T3 and regulating the levels of both hormones in the body. Dysfunction in these enzymes can lead to thyroid disorders, highlighting the importance of their molecular function.'
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Proteins (1)

Compounds (2)