Thyroglobulin
| Thyroglobulin | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 2749 amino acids | |
| Secondary to quaternary structure | Homodimer | |
| Isoforms | 2 | |
| Identifier | ||
| Gene names | TG ; AITD3; TGN | |
| External IDs | ||
| Occurrence | ||
| Homology family | Thyroglobulin | |
| Parent taxon | Euteleostomi | |
Thyroglobulin ( TG ) is a protein of the thyroid gland on which the thyroid hormone synthesis of thyroxine and triiodothyronine takes place. During this process, the iodine atoms are bound to the tyrosine components of the thyroglobulin (iodination). It is the main component of the colloid of the thyroid gland. It is made in the thyrocytes.
The detection of thyroglobulin in humans proves the presence of thyroid tissue and is therefore particularly suitable for searching for residual tissue after a thyroid removal. Elevated antibodies against thyroglobulin (TG-AK or TAK) indicate an autoimmune disease of the thyroid gland such as B. Hashimoto's thyroiditis . Mutations in the TG gene can cause goiter .
Thyroglobulin was discovered in 1899 by Adolph Oswald (1870–1956).
properties
There is a ( heterogeneous ) iodine - glycoprotein with a molecular mass of about 660 kDa . It must not be confused with the similar-sounding " thyroxine-binding globulin " (TBG).
Under the influence of thyrotropin , thyroglobulin is usually synthesized in the follicular cells of the thyroid gland as a precursor to thyroxine and triiodothyronine .
Thyroglobulin as a tumor marker
In the context of carcinoma follow-up care, a main method for searching for residual tissue is scintigraphy . However, on the one hand, cancerous cells can almost have lost their massive ability to accumulate iodine , and on the other hand, recurrent tissue can be so small or so deep under other tissue that it can no longer be scintigraphically scanned. V. a. in papillary and follicular thyroid carcinoma , thyroglobulin is an important additional test value.
In the treatment of thyroid carcinoma , all of the thyroid tissue that can be reached is surgically removed. Depending on the tumor histology and stage, the subsequent radioiodine therapy destroys as many thyroid cells as possible . If thyroglobulin can be detected in later controls, this is a clear indication of thyroid cells - benign or malignant.
Individual evidence
- ↑ UniProt entry
- ↑ A. Oswald: The protein bodies of the thyroid. In: Journal of Physiological Chemistry. Volume 27, 1899, p. 14.
- ↑ wikibooks: Thyroid: History .
- ↑ A. Oswald: On the knowledge of thyroglobulin. In: [Hoppe-Seyler's] journal for physiological chemistry. Volume 32, Issue 1-2, pp. 121-144.
Web links
- Thyroglobulin at laborlexikon.de
