5′-Nucleotidase Assay Kit (5’-NT)
For the in vitro quantitative determination of 5’nucleotidase activity in human serum or plasma
5’-NT is an enzyme catalyzing the hydrolysis of nucleoside-5’-monophosphates to nucleosides and inorganic phosphate. The enzyme is widely distributed in human and animal tissues. The activity present in sera is released from the membrane of liver cells by bile salts and has been used as a marker for liver disease[1]. Increased enzyme levels in sera are associated with certain forms of liver disease, such as intra or extra hepatic obstruction and particularly in cases of hepatic carcinoma as well as in mastectomy patients with recurrent metastases. The diagnostic value of 5’-NT has been shown to be superior to other liver enzymes, especially in cases of liver metastasis.
The 5’-NT assay is based on the enzymatic hydrolysis of 5’-monophosphate (5’-IMP) to form inosine which is converted to hypoxanthine by purine nucleoside phosphorylase (PNP). Hypoxanthine is then converted to uric acid and hydrogen peroxide (H2O2) by xanthine oxidase (XOD). H2O2 is further reacted with N-Ethyl-N(2-hydroxy-3-sulfopropyl)-3-methylaniline (EHSPT) and 4-aminoantipyrine (4-AA) in the presence of peroxidase (POD) to generate quinone dye which is monitored in a kinetic manner. The entire enzymatic reaction scheme is shown below.
5’-NT
IMP + H2O → Inosine + Pi
PNP
Inosine + Pi → Hypoxanthine + Ribose 1-phosphate
XOD
Hypoxanthine + 2H2O + 2O2 → Uric acid +2H2O2
POD
2H2O2+4-AA+EHSPT → 4H2O+Quinone dye (λmax=556 nm)
- Eroglu A. Activities of adenosine deaminase and 5′- nucleotidase in cancerous and noncancerous human cdorectal tissues[J]. Med Oneol 2000; 17(4) :319 – 24.1
- Alain Bertrand and Jean Buret, A one-step determination of 5’-nucleotidase using a centrifugal analyzer. Clinica Chimica Acta,119(1982)275-284.
- By Z. Ahmed and J.L.Reis, The Activation and Inhibition of 5-Nucleotidase. Clin Chem. 1998，69 （11），102－106.