Preparation and specification
| Appearance | Yellow amorphous powder, lyophilized |
| Protein purity | ≥90% (from SDS-PAGE) |
| Activity | ≥4 U/mg solid |
| Catalase | ≤0.01% |
| ATPase | ≤0.005% |
| Glucose oxidase | ≤0.03% |
| Cholesterol oxidase | ≤0.003% |
Properties
| ECnumber | 1.5.3 (Recombinantfrom microorganism) | |
| Molecular weight | 60 kDa (SDS-PAGE) | |
| Isoelectric point | 6.4 | |
| Michaelis constants | 4.0×10-3 M (fructosyl-Val-His) | |
| Inhibitors | Hg2+,Pb2+ | |
| Optimum pH | pH 6.5-7.5 | Fig.1 |
| Optimum temperature | 37℃ | Fig.2 |
| pH stability | pH 6.5-9.5 (25 ℃, 16 h) | Fig.3 |
| Thermal stability | Below 40℃ (pH8.0,30 min) | Fig.4 |
| Storage stability | At least one year at -25 ～-15 ℃ | Fig.5 |
| Stabilizers | Glycerol, trehalose | |
Applications
The enzyme is useful for the determination of fructosyl-peptide and fructosyl-L-amino acid.
Unit definition
One unit (U) is defined as the amount of enzyme which produces 1 μmol of H2O2 per min under the conditions described below.
