5'-Nucleotidase (5'-NT)

5'-Nucleotidase is an enzyme that catalyzes the hydrolysis of phosphate groups from nucleoside monophosphates at the 5' position, producing corresponding nucleosides and inorganic phosphate[2][4]. It exists both as a soluble cytoplasmic enzyme involved in nucleotide metabolism and as a membrane-bound ectoenzyme—most notably known as CD73—which plays a key role in generating extracellular adenosine from AMP[2][6]. This activity regulates purinergic signaling with broad implications for immune modulation, vascular function, inflammation control, and cancer biology[1][2][6]. The enzyme has wide substrate specificity but primarily acts on AMP; its activity can influence resistance mechanisms against certain chemotherapeutic agents by dephosphoryting active drug metabolites[5].

Other names

Ecto-5'-nucleotidaseCD73 (for the membrane-bound form)EC 3.1.3.55′-NTAMPase (in some contexts)

Drugs targeting this enzyme typically act as inhibitors to block the conversion of AMP to adenosine, thereby reducing immunosuppressive signaling mediated by adenosine in the tumor microenvironment or inflamed tissues.