Halogen Bonding in Biomimetic Deiodination of Thyroid Hormones, their Metabolites and Halogenated Nucleosides.

Halogen Bonding in Biomimetic Deiodination of Thyroid Hormones, their Metabolites and Halogenated Nucleosides. Chembiochem. 2019 Nov 26;: Authors: Mondal S, Manna D, Raja K, Mugesh G Abstract Thyroid hormones (THs) are key players of the endocrine system, and play pivotal roles in carbohydrate and fat metabolism, protein synthesis, overall growth and brain development. Thyroid gland predominantly produces thyroxine or 3,5,3',5'-tetraiodothyronine (T4) as a prohormone and three isoforms of mammalian selenoenzyme, iodothyronine deiodinase (DIO1, DIO2 and DIO3) catalyze the regioselective deiodination of T4 to produce the biologically active and inactive metabolites. While DIO1 catalyzes both 5- and 5'-deiodination of T4, DIO2 and DIO3 selectively mediates 5- and 5'-deiodinations, respectively. In this review, we discuss the regioselective deiodination of THs by organochalcogen compounds. Naphthyl-based compounds containing sulphur and/or selenium at the peri-positions mediate regioselective 5-deiodination of THs and detailed mechanistic studies revealed that the heterolytic cleavage of C-I bond is facilitated by the formation of cooperative Se/S•••I halogen bond and Se/S•••Se chalcogen bond. We also discuss the biomimetic deiodination of several TH metabolites, including sulphated THs, iodothyronamines and iodotyrosines. A brief discussion on the dehalogenation of halogenated nucleosides and nucleobases by organochalcogen c...
Source: Chembiochem - Category: Biochemistry Authors: Tags: Chembiochem Source Type: research