N8264

Nucleoside Phosphorylase from microorganisms

lyophilized powder, ≥10 units/mg protein

• Synonym(s): Nucleoside Phosphorylase bacterial, PNP, Purine nucleoside phosphorylase, Purine nucleoside:orthophosphate ribosyltransferase
• CAS Number: 9030-21-1
• Enzyme Commission number: 2.4.2.1 (BRENDA, IUBMB)
• EC Number: 232-857-3
• MDL number: MFCD00131739
• UNSPSC Code: 12352204

Properties

• form: lyophilized powder
• specific activity: ≥10 units/mg protein
• mol wt: ~120 kDa
• composition: Protein, 40-80%
• storage temp.: −20°C
• InChI: 1S/C10H12N4O4/c15-2-6-7(16)8(17)10(18-6)14-4-13-5-1-11-3-12-9(5)14/h1,3-4,6-8,10,15-17H,2H2/t6-,7-,8-,10-/m1/s1
• InChI key: MRWXACSTFXYYMV-FDDDBJFASA-N

Description

General description

Nucleoside Phosphorylase are trimeric and have a molecular mass of about 100 kDa. Each monomer consists of a mixed β-sheet core flanked by eight α-helices and a purine binding in hydrophobic pocket.

Nucleoside phosphorylase is an enzyme important for the biosynthesis of nucleosides.

Application

Nucleoside Phosphorylase from microorganisms has been used:

• in phosphopentomutase assay for adenosine synthesis
• for the conversion of 7-methylthioguanosine to 7-methylthioguanine
• in the synthesis of cytokinins in lyophilized cotton plant samples

Nucleoside phosphorylase is used in coupled enzyme systems to measure protein dephosphorylation.

Biochem/physiol Actions

Nucleoside Phosphorylase catalyzes the synthesis of nucleoside derivatives.

This enzyme is useful for enzymatic determination of inorganic phosphorus, 5′-nucleotidase and adenosine deaminase when coupled with xanthine oxidase (XTO-212) and uricase (UAO-201, UAO-211). Purine nucleoside phosophorylase has shown the ability to perform both phosphorylosis and synthesis of purine deoxy- and ribonucleosides. It has also been found that membrane-associated nucleoside phosphorylases may have a transmembranal orientation with their base and ribose-1-P binding sites on opposite sides of the membrane.

Catalyzes the following reaction:purine nucleoside + phosphate = purine + alpha-D-ribose 1-phosphate

Physical properties

Isoelectric point : 4.1 +/- 0.1
Michaelis constants : 6.4 x 10^-5M (Inosine), 3.2x10^-4M (Pi)
Inhibitors : p-Chloromercuribenzoate, SDS, Hg⁺⁺, Ag⁺Optimum pH : 7.5 - 8.0
Optimum temperature : 65o^C
pH Stability : pH 6.0 - 9.0 (30o^C, 16hr)
Thermal stability : below 60o^C (pH 7.7, 30min)

Unit Definition

One unit will cause the phosphorolysis of 1.0 μmole of inosine to hypoxanthine and ribose 1-phosphate per min at pH 7.4 at 25 °C.

Physical form

Lyophilized powder containing potassium gluconate, mannitol and EDTA

Safety Information

• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 3
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves