Preparation and specification
| Appearance | White amorphous powder, lyophilized |
| Purity(SDS-PAGE) | ≥90.0% |
| Enzyme powder specific activity | ≥55.0 U/mg |
| Glucose-6-phosphate dehydrogenase | ≤0.01% |
| Lactate dehydrogenase | ≤0.005% |
| Glutamate dehydrogenase | ≤0.001% |
| Malate dehydrogenase | ≤0.01% |
| Hexokinase | ≤0.01% |
Properties
| EC number | 1.1.1.50 (Recombinant from microorganism) | |
| Molecular weight | 30 kDa (SDS-PAGE) | |
| Isoelectric point | 5.2 | |
| Michaelis constants | 3.6×10-5 M (Androsterone), 4.7×10-5 M (NAD+) | |
| Inhibitors | Fe3+, Co2+, Cu2+, Mn2+, Zn | |
| Optimum pH | 8.5-9.5 | Fig. 1 |
| Optimum temperature | 55 ℃ | Fig. 2 |
| pH stability | pH 6.0 - 9.0 (25 ℃, 16 h) | Fig. 3 |
| Thermal stability | Below 37 ℃ (pH 9.0, 30 min) | Fig. 4 |
| Storage stability | At least one year at -25 ～-15 ℃ | Fig. 5 |
| Stabilizers | BSA | |
Applications
This enzyme is useful for enzymatic cycling determination of bile acid when coupled with thio–NAD and NADH.
Unit definition
One unit (U) is defined as the amount of enzyme which produces 1 μmol of NADH per min under the conditions described below.
