thyroxine-binding globulin , także: thyroxine-binding protein

Most of the T3 in the blood is attached to thyroxine-binding globulin.

However, it is speculated that the δ-conformation may be adopted by Thyroxine-binding globulin during thyroxine release.

Thyroglobulin should not be confused with Thyroxine-binding globulin, a carrier protein responsible for carrying the thyroid hormones in the blood.

It can also be measured as total triiodothyronine, which also depends on the triiodothyronine that is bound to thyroxine-binding globulin.

In the blood, thyroxine and triiodothyronine are partially bound to thyroxine-binding globulin, transthyretin and serum albumin.

Iodine deficiency, hypothyroidism, and low serum concentrations of thyroxine-binding globulin were significantly related to Kashin-Beck disease.

Thyroxine-binding globulin (TBG) binds thyroid hormone in circulation.

Thyroxine-binding globulin, carries the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3)

Thyroxine-binding globulin and cortisol-binding globulin transport the sterol hormones thyroxine and cortisol, respectively (Figure 3).

An increased thyroxine-binding globulin results in an increased total thyroxine and total triiodothyronine without an actual increase in hormonal activity of thyroid hormones.

The FTI can help tell if abnormal amounts of T4 are present because of abnormal amounts of thyroxine-binding globulin.

For example, the native (S) form of thyroxine-binding globulin has high affinity for thyroxine, whereas the cleaved (R) form has low affinity.

A related parameter is the free thyroxine index, which is total thyroxine multiplied by thyroid hormone uptake, which, in turn, is a measure of the unbound thyroxine-binding globulins.

In comparison to levothyroxine (T), liothyronine has a faster onset of action as well as a shorter biological half-life, which may be due to less plasma protein binding to thyroxine-binding globulin and transthyretin.

The lipophilicity of T and T requires their binding to the protein carrier thyroid-binding protein (TBG) [ thyroxine-binding globulins, thyroxine binding prealbumins, and albumins] for transport in the blood.