Iodination of Tyrosyls in Thyroglobulin

Cause Thyroiditis Generates Neoantigenic Determinants That Iodination of Tyrosyls in Thyroglobulin

Defective thyroglobulin synthesis in an experimental rat thyroid tumor: iodination and thyroid hormone synthesis in isolated tumor thyroglobulin.

Purified rat tumor thyroglobulin from the experimental rat thyroid tumor, line 1-1C2, was studied for its thyroid hormone content after in vivo and in vitro iodination and compared with normal and desialylated normal rat thyroglobulin. Tumor thyroglobulin had a very low sialic acid and iodine content; after in vivo iodination it contained only small amounts of triiodothyronine (T3) and no detec...

Enzymatic iodination of tyrosine and thyroglobulin with chloroperoxidase.

1. Crystalline chloroperoxidase is effective in catalyzing the iodination of tyrosine or thyroglobulin when supplemented with HzOz, or with the H20z-generating system, glucoseglucose oxidase. The iodination reaction is very rapid at low concentrations of iodide (5 X 10-5 M), and at low concentrations of tyrosine (1 X 10V4 M) or thyroglobulin (0.33 mg per ml). 2. Iodide is rapidly bound as 3-iod...

Relationship between iodination and the polypeptide chain composition of thyroglobulin.

Thyroglobulin was isolated from thyroid glands of normal guinea pigs and from animals treated with thiouracil. These preparations were fractionated by isopyknic centrifugation in RbCl into proteins of varying iodine content. When the disulfide bonds of these protein fractions were reduced and analyzed by polyacrylamide gel electrophoresis in Na dodecyl-SO4, t hree species were observed with mol...

Iodination and oxidation of thyroglobulin catalyzed by thyroid peroxidase.

The kinetics of iodination and oxidation of hog thyroglobulin were studied with purified hog thyroid peroxidase and the results were compared with the reactions of free tyrosine. From Lineweaver-Burk plots and on the basis of a value of 0.83 for delta epsilon mM at 289 nm/iodine atom incorporated, the rate constant for transfer of an assumed enzyme-bound iodinium cation to thyroglobulin was est...