Purine Nucleoside Phosphorylase

  title={Purine Nucleoside Phosphorylase},
  author={Johanna D. Stoeckler and Robert E. Parks},
It has long been appreciated that purine nucleoside phosphorylase (PNP; purine nucleoside: orthophosphate ribosyltransferase, EC may play a role in cancer chemotherapy by catalyzing the degradation of potentially cytotoxic purine deoxynucleoside analogs, e.g., 2′-deoxy-6-thioguanosine. More recently, the identification of an immunodeficiency disorder associated with a deficiency in PNP (Giblett et al., 1975) has drawn attention to this enzyme as a possible target for the design of… 

Calf spleen purine nucleoside phosphorylase complexed with substrates and substrate analogues.

The bovine PNP structure reveals several new details of substrate and inhibitor binding, including two phosphate-induced conformational changes involving residues 33-36 and 56-69 and a previously undetected role for His64 in phosphate binding.

Purine nucleoside phosphorylase: allosteric regulation of a dissociating enzyme.

Purine nucleoside phosphorylase catalyzes the phosphorolysis of guanine or inosine to form the base and (d)ribose-1-P; the enzyme has therefore been defined as catabolic.

Purine nucleoside phosphorylase as a cytosolic arsenate reductase.

  • Z. GregusB. Németi
  • Biology, Chemistry
    Toxicological sciences : an official journal of the Society of Toxicology
  • 2002
The hypothesis that PNP is responsible for the thiol- and purine nucleoside-dependent reduction of AsV to AsIII by rat liver cytosol is tested and it is found that P NP reduces AsVto AsIII, using AsV instead of phosphate in the reaction above.

Inhibition and Structure of Toxoplasma gondii Purine Nucleoside Phosphorylase

This first crystal structure of TgPNP describes the basis for discrimination against 5′-methylthioinosine and similarly5′-hydroxy-substituted immucillins; structural differences reflect the unique adaptations of purine salvage pathways of Apicomplexa.

Design of Purine Nucleoside Phosphorylase Inhibitors Using X-Ray Crystallography

Purine nucleoside phosphorylase (PNP) catalyzes the reversible phosphorolysis of ribonucleosides and 2’-deoxyribonucleosides to the free base and ribose-1-phosphate (1–4). Although equilibrium favors

Low-molecular-mass purine nucleoside phosphorylase: characterization and application in enzymatic synthesis of nucleoside antiviral drugs

The PNP816 or engineered strain XBlue (pQE-816) had a higher catalytic activity than other rPNPs or engineered strains during the enzymatic synthesis of ribavirin, which suggested that the low-molecular-mass homotrimer derived from microorganisms has higher catalytical activity for synthesis of nucleoside antiviral drugs.

Anopheles gambiae purine nucleoside phosphorylase: catalysis, structure, and inhibition.

The purine salvage pathway of Anopheles gambiae, a mosquito that transmits malaria, has been identified in genome searches on the basis of sequence homology with characterized enzymes and is consistent with enzymatic transition state predictions of enhanced transition-state analogue binding in enzymes with enhanced catalytic efficiency.



Lymphospecific toxicity in adenosine deaminase deficiency and purine nucleoside phosphorylase deficiency: possible role of nucleoside kinase(s).

It is proposed that in adenosine deaminase and purine nucleoside phosphorylase deficiency, toxic deoxyribonucleosides produced by many tissues are selectively trapped in lymphocytes byosphorylating enzyme(s).

Purine nucleoside phosphorylase from human erythroyctes. II. Kinetic analysis and substrate-binding studies.

Abstract Purified purine nucleoside phosphorylase (purine riboside: orthophosphate ribosyltransferase, EC from human erythrocytes has been subjected to a kinetic analysis, including initial

Human erythrocytic purine nucleoside phosphorylase: reaction with sugar-modified nucleoside substrates.

The kinetic parameters (Km and Vmax) of sugar-modified analogues of inosine and guanosine have been determined with human erythrocytic purine nucleoside phosphorylase (PNP), indicating that the 5'-hydroxyl and the orientation of the 5'hydroxy-methyl group are not important for binding.

Adenine as substrate for purine nucleoside phosphorylase.

Adenine is a competitive inhibitor of purine nucleoside phosphorylase from Sarcoma 180 ascites cells and an inhibition constant, Ki, was determined for adenine with this enzyme and with selenoguanine as the variable substrate.

Proposed explanation for S-adenosylhomocysteine hydrolase deficiency in purine nucleoside phosphorylase and hypoxanthine-guanine phosphoribosyltransferase-deficient patients.

We have examined the basis for the recently reported, but unexplained deficiency of S-adenosylhomocysteine hydrolase (AdoHcyase) in the erythrocytes of patients with genetic deficiencies of purine

Chinese hamster purine nucleoside phosphorylase.

  • G. Milman
  • Biology, Chemistry
    Methods in enzymology
  • 1978