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
• Quality Level: 200
• specific activity: ≥10 units/mg protein
• mol wt: ~120 kDa
• composition: Protein, 40-80%
• storage temp.: −20°C
• SMILES string: [n]2(c3ncncc3nc2)[C@@H]1O[C@@H]([C@H]([C@H]1O)O)CO
• 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.[1] Each monomer consists of a mixed β-sheet core flanked by eight α-helices and a purine binding in hydrophobic pocket.[1]

Nucleoside phosphorylase is an enzyme important for the biosynthesis of nucleosides. [2]

Application

Nucleoside Phosphorylase from microorganisms has been used:

• in phosphopentomutase assay for adenosine synthesis[3]
• for the conversion of 7-methylthioguanosine to 7-methylthioguanine[4][5]
• in the synthesis of cytokinins in lyophilized cotton plant samples[6]

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

Biochem/physiol Actions

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

Nucleoside Phosphorylase catalyzes the synthesis of nucleoside derivatives.[7]

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. [8] 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. [9]

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: 11 - Combustible Solids
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable
• ppe: Eyeshields, Gloves, type N95 (US)