Biomaterial Database

The importance of thyroglobulin structure in thyroid peroxidase-catalyzed conversion of diiodotyrosine to thyroxine. 1977

L Lamas, and A Taurog

We have previously demonstrated that thyroid peroxidase (TPO) not only catalyzes the iodination of thyroglobulin and other proteins, but that it also catalyzes the intramolecular conversion of DIT residues to T4 (coupling reaction). The present study was designed to determine whether the native structure of thyroglobulin contributes to the efficiency of TPO-catalyzed coupling. Two lines of evidence are presented in support of the view that the conformation of thyroglobulin is important for TPO-catalyzed coupling. The first was based on comparison of T4 yields in thyroglobulin and other proteins. The second involved the effect of guanidine pretreatment on T4 yields in thyroglobulin. Both types of experiment provided evidence that the native structure of thyroglobulin contributes to the efficiency of the coupling reaction. Specificity of thyroid peroxidase activity, on the other hand, does not appear to be of importance in the coupling reaction.

UI	MeSH Term	Description	Entries
D007453	Iodide Peroxidase	A hemeprotein that catalyzes the oxidation of the iodide radical to iodine with the subsequent iodination of many organic compounds, particularly proteins. EC 1.11.1.8.	Iodinase,Iodothyronine 5'-Deiodinase,Iodothyronine Deiodinase,Iodotyrosine Deiodase,Thyroid Peroxidase,Thyroxine 5'-Deiodinase,Thyroxine 5'-Monodeiodinase,5'-Deiodinase,Deiodinase,Iodotyrosine Deiodinase,Monodeiodinase,Reverse Triiodothyronine 5'-Deiodinase,T4-5'-Deiodinase,T4-Monodeiodinase,Tetraiodothyronine 5'-Deiodinase,Thyroxine Converting Enzyme,Triiodothyronine Deiodinase,5' Deiodinase,5'-Deiodinase, Iodothyronine,5'-Deiodinase, Reverse Triiodothyronine,5'-Deiodinase, Tetraiodothyronine,5'-Deiodinase, Thyroxine,5'-Monodeiodinase, Thyroxine,Deiodase, Iodotyrosine,Deiodinase, Iodothyronine,Deiodinase, Iodotyrosine,Deiodinase, Triiodothyronine,Enzyme, Thyroxine Converting,Iodothyronine 5' Deiodinase,Peroxidase, Iodide,Peroxidase, Thyroid,Reverse Triiodothyronine 5' Deiodinase,T4 5' Deiodinase,T4 Monodeiodinase,Tetraiodothyronine 5' Deiodinase,Thyroxine 5' Deiodinase,Thyroxine 5' Monodeiodinase,Triiodothyronine 5'-Deiodinase, Reverse
D007784	Lactoperoxidase	An enzyme derived from cow's milk. It catalyzes the radioiodination of tyrosine and its derivatives and of peptides containing tyrosine.
D010544	Peroxidases		Ovoperoxidase
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D002364	Caseins	A mixture of related phosphoproteins occurring in milk and cheese. The group is characterized as one of the most nutritive milk proteins, containing all of the common amino acids and rich in the essential ones.	alpha-Casein,gamma-Casein,AD beta-Casein,Acetylated, Dephosphorylated beta-Casein,Casein,Casein A,K-Casein,Sodium Caseinate,alpha(S1)-Casein,alpha(S1)-Casein A,alpha(S1)-Casein B,alpha(S1)-Casein C,alpha(S2)-Casein,alpha-Caseins,beta-Casein,beta-Caseins,epsilon-Casein,gamma-Caseins,kappa-Casein,kappa-Caseins,AD beta Casein,Caseinate, Sodium,K Casein,alpha Casein,alpha Caseins,beta Casein,beta Caseins,beta-Casein Acetylated, Dephosphorylated,beta-Casein, AD,epsilon Casein,gamma Casein,gamma Caseins,kappa Casein,kappa Caseins
D004105	Diiodotyrosine	A product from the iodination of MONOIODOTYROSINE. In the biosynthesis of thyroid hormones, diiodotyrosine residues are coupled with other monoiodotyrosine or diiodotyrosine residues to form T4 or T3 thyroid hormones (THYROXINE and TRIIODOTHYRONINE).	Iodogorgoic Acid,Acid, Iodogorgoic
D005340	Fibrinogen	Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.	Coagulation Factor I,Factor I,Blood Coagulation Factor I,gamma-Fibrinogen,Factor I, Coagulation,gamma Fibrinogen
D006146	Guanidines	A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013954	Thyroglobulin