G6P-DH LEUC. MESENTEROIDES 1000 U

General description

Glucose-6-Phosphate Dehydrogenase (G6PD) is a ubiquitous enzyme which acts as a catalyst in producing pentose. It also produces NADPH for various biosynthetic and detoxification reactions. Sometimes G6PD provides an alternative to main glycolytic pathway for glucose utilization. It also has its application as DNA markers on X-chromosome.1

Specificity

Specificity: At pH 7.8, 25 °C: G6P-DH from Leuconostoc (LG6PDH) is highly specific for D-glucose-6-phosphate (K_m = 36 μM, NADP as coenzyme; 64 μM, NAD as coenzyme), but will use either NADP (K_m = 7.4 μM; relative rate 1.0) or NAD (K_m = 115 μM; relative rate 1.8) as coenzyme.
LG6P-DH does not react with fructose-6-phosphate, fructose-1,6-biphosphate, glucose-1-phosphate or ribose-1-phosphate. LG6P-DG will oxidize 2-deoxy-glucose-6-phosphate with NADP, but not with NAD as coenzyme. There is a slow reaction with D-glucose.
Heat inactivation: The ammonium sulfate suspension is not inactivated when heated to temperatures ≤ 50 °C for 10 minutes. At temperatures > 60 °C the enzyme is rapidly inactivated.

Application

Component of cofactor recycling systems for NADPH.

It was used in enzymatic determination of C6 phosphorylation of glycogen.

Quality

Contaminants: <0.001% CK, <0.01% GR and PGI each, <0.02% “NADH oxidase”, <0.05% HK, <0.001% 6-PGDH

Unit Definition

Unit Conversion: One unit (U) [+25 °C] ≈ 1.18 U [+30 °C] ≈ 1.45 U [+37 °C], all with NAD as coenzyme

Unit Definition: One unit (U) LG6P-DH oxidizes 1 mol of glucose-6-phosphate and reduces 1 mol of NAD in 1 minute at +25 °C and pH 7.8.

Physical form

Solution of 1,000 U in 1 ml 3.2 M ammonium sulfate, pH approximately 6

Preparation Note

Activator: HCO^3- (≤ 0.3 M) activates slightly.

Analysis Note

Absorbance of purified enzyme: 1.15 (1 mg enzyme/ml, 280.5 nm)

Other Notes

For life science research only. Not for use in diagnostic procedures.