Human Thyroid-Stimulating Hormone (TSH)

Thyroid-stimulating hormone (TSH) is produced by the
pituitary gland at the base of the brain. It has a molecular
mass of approximately 28 000 Da. TSH is a member of
the glycoprotein hormones family, which consists of TSH,
luteinizing hormone (LH), follicle-stimulating hormone (FSH),
and chorionic gonadotropin (CG). Glycoprotein hormones are
heterodimers that consist of α- and β-subunits. The α-subunit
is the same for all glycoprotein hormones – TSH, LH, FSH,
and CG. Meanwhile, the β-subunit is specific for each hormone.
However, a high degree of homology exists between human
TSH, LH, FSH, and CG β-subunit sequences.