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)
Activators/inhibitors: 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