Purine Nucleoside Phosphorylase Activity Assay Kit (Colorimetric) (ab204707) is an assay where the hypoxanthine
formed by the breakdown of inosine is further converted to uric acid using a developer. The uric acid is measured at a
wavelength of OD=293 nm. Limit of quantification is 0.1 μU recombinant Purine Nucleoside Phosphorylase.
This product is manufactured by BioVision, an Abcam company and was previously called K768 Purine Nucleoside
Phosphorylase Activity Assay Kit (Colorimetric). K768-100 is the same size as the 100 test size of ab204707.
Purine Nucleoside Phosphorylase (PNP, E.C. 2.4.2.1.) is an enzyme involved in purine metabolism and it catalyzes the
cleavage of the glycosidic bond of ribo- or deoxyribonucleosides, in the presence of inorganic phosphate as a second
substrate, to generate the purine base and ribose-1-phosphate or deoxyribose-1-phosphate. It is one of the enzymes
of the nucleotide salvage pathways that allow the cell to produce nucleotide monophosphates when the de novo
synthesis pathway has been interrupted or is non-existent (as is the case in the brain). PNP is a cytosolic enzyme. PNP
deficiency disease leads to toxic buildup of deoxyguanosine in T-cells leading to T-lymphocytopenia with no apparent
effects on B-lymphocyte function. Inhibition of PNP is an important target for chemotherapeutic applications and
treatment of T-cell mediated autoimmune diseases. PNP deficiency is also associated with neurological problems.
