Thymidine kinase

• OMIM: 188300
• UniProt: P04183
• MGI: 98763

The thymidine kinase ( TK) is the one enzyme in all living things, the deoxythymidine to Desoxythymidinphosphat ( dTMP ) converts. Therefore, it is essential in the construction of the DNA. In particular, budding cells in interphase produce this enzyme. The mitochondria in eukaryotic cells have their own variant.

Catalyzed reaction

ATP → ADP

Deoxythymidine reacts with ATP to dTMP and ADP. Of the nucleoside thus was the nucleotide which can be incorporated into the DNA.

Despite its name thymidine kinases of many organisms are relatively nonspecific. So also cytosine and uridine, and their deoxy derivatives, and also guanosine analogs such as acyclovir can be phosphorylated.

Importance in medicine

As the thymidine kinase ( TK) is an enzyme that is involved in the incorporation of the nucleoside thymidine into the DNA, its concentration is a measure of mitotic activity of cells. In particular, in malignant diseases of the hematopoietic and lymphatic system its value is higher than the normal value of < 5 U / l and is thus a tumor marker in acute and chronic leukemias, in non-Hodgkin 's lymphoma and multiple myeloma, a statement of the progress and can give the prognosis of the disease. In the laboratory, the TK is determined by the radioimmunoassay ( RIA).