KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
30 | - |
beta-D-glucose | pH 6.0, 25°C, glycosylated enzyme | Aspergillus niger | |
33 | - |
beta-D-glucose | pH 6.0, 25°C, deglycosylated enzyme | Aspergillus niger |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
80000 | - |
2 * 80000, PAGE under dissociating conditions, glycosylated enzyme | Aspergillus niger |
157000 | - |
PAGE under non-dissociating conditions, glycosylated enzyme | Aspergillus niger |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Aspergillus niger | P13006 | - |
- |
Posttranslational Modification | Comment | Organism |
---|---|---|
glycoprotein | approx. 95% of the carbohydrate moiety is cleaved from the protein by incubation of glucose oxidase with endoglycosidase H and alpha-mannosidase. Cleavage of the carbohydrate moiety effects a 23-30% decrease in the molecular weight and a reduction in the number of isoforms of glucose oxidase. No significant changes were observed in the circular dichroism spectra of the deglyeosylated enzyme. Other properties, such as thermal stability, pH and temperature optima of glucose oxidase activity and substrate specificity are not affected. However, removal of the carbohydrate moiety marginally affect the kinetics of glucose oxidation and stability at low pH. From these results it appears that the carbohydrate chain of glucose oxidase does not contribute significantly to the structure, stability and activity of glucose oxidase | Aspergillus niger |
Purification (Comment) | Organism |
---|---|
purification to homogeneity by hydrophobic interaction and ion-exchange chromatography | Aspergillus niger |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
beta-D-glucose + O2 | D-glucose is oxidised at a much faster rate than 2-deoxy-D-glucose and D-mannose, whereas L-glucose, D-galactose, D-arabinose, D-xylose are not oxidised | Aspergillus niger | D-glucono-1,5-lactone + H2O2 | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | 2 * 80000, PAGE under dissociating conditions, glycosylated enzyme | Aspergillus niger |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Aspergillus niger |
Temperature Minimum [°C] | Temperature Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | 50 | the activity of the glycosylated and deglycosylated enzyme increases 2fold from 25°C to 55°C | Aspergillus niger |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
50 | - |
stable up to. At 50°C the enzyme is inactivated by 30% over a period of 11 h. The thermal stability is unaffected by the depletion of carbohydrate | Aspergillus niger |
60 | - |
t1/2: 60 min | Aspergillus niger |
70 | - |
t1/2: 5 min | Aspergillus niger |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
815 | - |
beta-D-glucose | pH 6.0, 25°C, deglycosylated enzyme | Aspergillus niger | |
920 | - |
beta-D-glucose | pH 6.0, 25°C, glycosylated enzyme | Aspergillus niger |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5.5 | 6 | - |
Aspergillus niger |
6 | - |
assay at | Aspergillus niger |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
4 | 7 | more than 90% of the maximum activity of glycosylated and deglycosylated enzyme form is observed between pH 4.0-7.0. Outside this range activity decreases rapidly | Aspergillus niger |
pH Stability | pH Stability Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
the deglycosylated enzyme is less stable at low pH | Aspergillus niger |
5 | - |
deglycosylation has no marked effect on the stability of the enzyme above pH 5 | Aspergillus niger |
9 | - |
at alkaline pH, particularly at and above pH 9.0, the glycosylated and the declycosylated enzyme are relatively unstable | Aspergillus niger |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
24.7 | - |
beta-D-glucose | pH 6.0, 25°C, deglycosylated enzyme | Aspergillus niger | |
30.7 | - |
beta-D-glucose | pH 6.0, 25°C, glycosylated enzyme | Aspergillus niger |