thyrokinase

Thyrokinase is a general term that has been used historically to refer to enzymes involved in the phosphorylation of iodine, a crucial step in the synthesis of thyroid hormones. Specifically, it relates to the enzyme thyroid peroxidase (TPO). TPO is a heme-containing enzyme that catalyzes the iodination of tyrosine residues on thyroglobulin and the subsequent coupling of these iodotyrosines to form thyroxine (T4) and triiodothyronine (T3). These thyroid hormones are essential for regulating metabolism, growth, and development in vertebrates.

The term thyrokinase is less commonly used in modern scientific literature, with thyroid peroxidase being the preferred and more precise designation for the enzyme responsible for these functions. Autoantibodies against TPO are frequently found in individuals with autoimmune thyroid diseases, such as Hashimoto's thyroiditis and Graves' disease, making TPO a significant target in immunological studies of thyroid function. Research into the structure, function, and regulation of TPO continues to be important for understanding thyroid physiology and pathology.