deiodinase


Also found in: Wikipedia.

deiodinase

an enzyme that deiodinates two of the iodinated amino acids (iodothyrosines) within the thyroid gland. Selenium-dependent deiodinase I converts thyroxine (T4) to triiodothyronine (T3), the more active thyroid hormone.
References in periodicals archive ?
A combination of T3 and T4 thyroxine is usually preferred, as deiodinase conversion of T4 to T3 is thought to be compromised in these settings (2).
An emerging concept in this field is that TH s pleiotropic actions can be amplified or attenuated at cell level by the deiodinase enzymes that can increase (D2) or decrease (D3) the active TH concentration regardless of hormone plasma levels.
The peripheral metabolism of thyroid hormones is catalyzed by deiodinase enzymes.
Selenium is implicated in antioxidant functions, and selenocysteine complex is essential in the active centres of Se-enzymes that carry out redox reactions, glutathione peroxidase (GPx), thyroid hormone deiodinase families and thioredoxinreductase (Tapiero et al.
Once T4 reaches the peripheral tissues, it is converted into its biologically active form, triiodothyronine (T3), by the deiodinase enzyme.
However, more recent work has shown that a relatively common polymorphism of the deiodinase 2 gene known as Thr92Ala may predict less responsiveness of psychological symptoms of hypothyroidism to optimal LT4 monotherapy.
Huang SA, Tu HM, Harney JW, et al: Severe hypothyroidism caused by type 3 iodothyronine deiodinase in infantile hemangiomas.
Selenium as a causative factor for goitre formation has been explained by diminished activity of selenocysteine enzymes in thyroid, notably glutathione peroxidase and deiodinase type-1 in selenium deficiency (29,30).
She said one of the enzymes that control thyroid hormone levels in the fetal brain is the iodothyronine deiodinase type III, or Dio3.
T3 is the thyroxine molecule that has lost one iodine atom, due to the action of deiodinase, a de-iodinating enzyme.