罗氏原料11293206103

Glucose-6-phosphate Dehydrogenase 11 293 206 103
(G6P-DH)
from Leuconostoc mesenteroides, expressed in E. coli,
lyophilizate
Dehydrogenase, that catalyzes the oxidation of Glucose-6-phosphate.
Application
Use Glucose-6-phosphate Dehydrogenase for the determination of blood
glucose or creatine kinase.
Benefits
Rely on the proven diagnostic quality of this product.
EC 1.1.1.49
Properties
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 (NAD as coenzyme)
Activators/inhibitors:
Phosphate, 5 mmol/l: 100% (NAD), 80% (NADP)
Phosphate, 50 mmol/l: 100% (NAD), 80% (NADP)
Without Mg 2+ : 90% (NAD), 80% (NADP)
Mg 2+ , 3 mmol/l: 100% (NAD), 100% (NADP)
Mg 2+ , 30 mmol/l: 100% (NAD), 100% (NADP)
HCO 3- , 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 gluose-1P. 2-Deoxyglucose-6-P is
slowly oxidized with NAD (5%) and with NADP (4%).
Specification
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):
ATPase: ≤0.02
Creatine kinase: ≤0.001