A Chemical Model for the Inner-Ring Deiodination of Thyroxine by Iodothyronine Deiodinase

摘要

Iodothyronine deiodinases (IDs) are mammalian selenoen-zymes that play an important role in the activation and inactivation of thyroid hormones. The outer-ring (5') deiodination of the prohormone thyroxine (T4) by the type 1 and 2 deiodinases (ID-1 and ID-2) produces the biologically active hormone, 3,5,3'-triiodothyronine (T3). These two enzymes also catalyze the outer-ring deiodination of 3,3'.5'-triiodothyronine (reverse T3, rT3) to produce 3.3-diiodothyronine (T2) (Scheme 1).