IUBMB Enzyme Nomenclature


Accepted name: purine-nucleoside phosphorylase

Reaction: (1) purine ribonucleoside + phosphate = purine + α-D-ribose 1-phosphate
(2) purine 2'-deoxyribonucleoside + phosphate = purine + 2-deoxy-α-D-ribose 1-phosphate

Other name(s): inosine phosphorylase; PNPase (ambiguous); PUNPI; PUNPII; inosine-guanosine phosphorylase; purine deoxynucleoside phosphorylase; purine deoxyribonucleoside phosphorylase; purine nucleoside phosphorylase; purine ribonucleoside phosphorylase

Systematic name: purine-nucleoside:phosphate ribosyltransferase

Comments: Specificity not completely determined. Can also catalyse ribosyltransferase reactions of the type catalysed by EC, nucleoside ribosyltransferase.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9030-21-1


1. Agarwal, R.P. and Parks, R.E. Purine nucleoside phosphorylase from human erythrocytes. IV. Crystallization and some properties. J. Biol. Chem. 244 (1969) 644-647. [PMID: 5768862]

2. Friedkin, M. and Kalckar, H. Nucleoside phosphorylases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.), The Enzymes, 2nd edn., vol. 5, Academic Press, New York, 1961, p. 237-255.

3. Heppel, L.A. and Hilmoe, R.J. Phosphorolysis and hydrolysis of purine ribosides from yeast. J. Biol. Chem. 198 (1952) 683-694.

4. Kalckar, H.M. The enzymatic synthesis of purine ribosides. J. Biol. Chem. 167 (1947) 477-486.

5. Saunders, P.P., Wilson, B.A. and Saunders, G.F. Purification and comparative properties of a pyrimidine nucleoside phosphorylase from Bacillus stearothermophilus. J. Biol. Chem. 244 (1969) 3691-3697. [PMID: 4978445].

6. Tsuboi, K.K. and Hudson, P.B. Enzymes of the human erythrocyte. I. Purine nucleoside phosphorylase; isolation procedure. J. Biol. Chem. 224 (1957) 879-887.

[EC created 1961]

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