Glucose-6-phosphate Dehydrogenase (G6P-DH)
from Leuconostoc mesenteroides, expressed in E. coli, lyophilizate
For further processing only.
Glucose-6-phosphate Dehydrogenase (G6P-DH) material number and pack size: Material Number Pack Size 11293206103 custom fill
- Dehydrogenase, that catalyzes the oxidation of Glucose-6-phosphate.
- Use Glucose-6-phosphate Dehydrogenase for the determination of blood glucose or creatine kinase.
Nomenclature: D-glucose-6-phosphate:NAD(P)+ 1-oxidoreductase
Molecular weight: 110 kD (1) (2 identical subunits 55,000 D)
Isoelectric point: pH 4.6
Michaelis constants (Tris: 0.1 mol/L; pH 7.8, +25°C):
NAD: 1.4 x 10-4 mmol/L
NADP: 3.7 x 10-5 mmol/L
Glucose-6-P: 3.7 x 10-4 mmol/L (NAD as coenzyme)
Glucose-6-P: 2.0 x 10-4 mmol/L (NADP as coenzyme)
Phosphate, 5 mmol/L: 100% (NAD), 80% (NADP)
Phosphate, 50 mmol/L: 100% (NAD), 80% (NADP)
Without Mg2+: 90% (NAD), 80% (NADP)
Mg2+, 3 mmol/L: 100% (NAD), 100% (NADP)
Mg2+, 30 mmol/L: 100% (NAD), 100% (NADP)
HCO3-, 3 mmol/L: 100% (NAD), 100% (NADP)
Inhibitors: NADPH is a competitive inhibitor in the NAD-dependent reaction. Unlike the yeast enzyme, myristic acid, dehydroepiandrosterone and palmitoyl CoA do not inhibit.
pH optimum: 7.8 (see figure)
Temperature dependence: See figure
pH stability: 5.0-10.0 (see figure)
Thermal stability: Up to +40°C for native G6P-DH, up to +50°C for modified G6P-DH (see figure)
Buffer stability: Temperature stability can be significantly improved by the increase of ionic strength (see figure).
Stability of the lyophilizate: 100% residual activity after 3 weeks at +35°C
Specificity: G6P-DH is highly specific for glucose-6-phosphate and does not react with fructose-6-P, fructose-1,6-P2 or glucose-1P. 2-Deoxyglucose-6-P is slowly oxidized with NAD (5%) and with NADP (4%). Appearance: White or slightly yellowish lyophilizate
Solubility: Clear, colorless solution in water (c=10 mg/mL)
pH value (c=10 mg/mL, water): 6.5-7.5
Activity (+25°C, glucose-6-P, NAD): ≥600 U/mg lyophilizate
Specific activity (+25°C): ≥800 U/mg protein
Activity (+30°C): ≥750 U/mg lyophilizate
Activity (+37°C): ≥1,000 U/mg lyophilizate
Activity (+25°C, glucose-6-P, NADP ): No limit
Protein (Biuret): 0.7-0.9 mg/mg lyophilizate
Contaminants (expressed as percentage of Glucose-6-phosphate dehydrogenase activity):
Creatine kinase: ≤0.001
Glutamate dehydrogenase: ≤0.01
Glutathione reductase: ≤0.001
Hexokinase and GIucose dehydrogenase: ≤0.05
''NADH oxidase'': ≤0.02
''NADPH oxidase'': ≤0.0005
6-Phosphogluconate dehydrogenase (NAD as coenzyme): ≤0.001
6-Phosphogluconate dehydrogenase (NADP as coenzyme): ≤0.001
Phophoglucose isomerase : ≤0.01
Stability: At +2 to +8°C within specification range for 12 months. Store dry.