Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Al3+ | - |
Euglena gracilis | |
Br- | marked inhibition at 1 mM | Euglena gracilis | |
Ca2+ | - |
Euglena gracilis | |
EDTA | slight inhibition, but when the enzyme is incubated with EDTA 1 mM at 37°C for 3 min in the absence of sucrose and ferrous sulfate there is nearly complete inhibition | Euglena gracilis | |
F- | - |
Euglena gracilis | |
Hg2+ | complete inhibition at 1 mM | Euglena gracilis | |
I- | - |
Euglena gracilis | |
KCN | 96.4% inhibition at 1 mM | Euglena gracilis | |
Li+ | - |
Euglena gracilis | |
Mg2+ | - |
Euglena gracilis | |
Mn2+ | marked inhibition at 1 mM | Euglena gracilis | |
NaN3 | 91.5% inhibition at 1 mM | Euglena gracilis | |
Ni2+ | - |
Euglena gracilis | |
Zn2+ | - |
Euglena gracilis |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.056 | - |
H2O2 | substrate: L-ascorbic acid | Euglena gracilis | |
0.22 | - |
H2O2 | substrate: pyrogallol | Euglena gracilis | |
0.41 | - |
L-ascorbic acid | - |
Euglena gracilis | |
9.6 | - |
pyrogallol | - |
Euglena gracilis |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe | hemoprotein | Euglena gracilis |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
76000 | - |
gel filtration | Euglena gracilis |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-ascorbate + H2O2 | Euglena gracilis | the enzyme works for protection of cell membrane, by reducing the peroxide compounds generated endogenously from unsaturated fatty acids | dehydroascorbate + 2 H2O | - |
? | |
L-ascorbate + H2O2 | Euglena gracilis | physiological role of the enzyme: removal of H2O2, prevention of H2O2 accumulation | dehydroascorbate + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Euglena gracilis | - |
- |
- |
Purification (Comment) | Organism |
---|---|
using ultracentrifugation, column chromatography on DEAE-cellulose, ammonium sulfate precipitation and column chromatography on Sephadex G-150, DEAE-cellulose and CM-cellulose | Euglena gracilis |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
2.8 | - |
purified enzyme, electron donor: glutathione, electron acceptor: H2O2 | Euglena gracilis |
5.8 | - |
purified enzyme, electron donor: iodide, electron acceptor: H2O2 | Euglena gracilis |
18 | - |
purified enzyme, electron donor: reductic acid, electron acceptor: H2O2 | Euglena gracilis |
20.3 | - |
purified enzyme, electron donor: guaiacol, electron acceptor: H2O2 | Euglena gracilis |
132.2 | - |
purified enzyme, electron donor: L-ascorbic acid, electron acceptor: cumene hydroperoxide | Euglena gracilis |
142.1 | - |
purified enzyme, electron donor: D-araboascorbic acid, electron acceptor: H2O2 | Euglena gracilis |
172.8 | - |
purified enzyme, electron donor: L-ascorbic acid, electron acceptor: tert-butyl hydroperoxide | Euglena gracilis |
185.5 | - |
purified enzyme, electron donor: pyrogallol, electron acceptor: H2O2 | Euglena gracilis |
254 | - |
purified enzyme, electron donor: L-ascorbic acid, electron acceptor: H2O2 | Euglena gracilis |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
cytochrome c + H2O2 | no activity | Euglena gracilis | ? + H2O | - |
? | |
D-araboascorbic acid + H2O2 | 56% activity relative to L-ascorbate | Euglena gracilis | dehydroascorbate + H2O | - |
? | |
guaiacol + H2O2 | 8% activity relative to L-ascorbate | Euglena gracilis | ? | - |
? | |
iodide + H2O2 | 2.3% activity relative to L-ascorbate | Euglena gracilis | ? | - |
? | |
L-ascorbate + H2O2 | tert-butyl hydroperoxide and cumene hydroperoxide also serve as electron acceptor | Euglena gracilis | dehydroascorbate + H2O | - |
? | |
L-ascorbate + H2O2 | the enzyme works for protection of cell membrane, by reducing the peroxide compounds generated endogenously from unsaturated fatty acids | Euglena gracilis | dehydroascorbate + 2 H2O | - |
? | |
L-ascorbate + H2O2 | physiological role of the enzyme: removal of H2O2, prevention of H2O2 accumulation | Euglena gracilis | dehydroascorbate + 2 H2O | - |
? | |
L-ascorbic acid + cumene hydroperoxide | - |
Euglena gracilis | dehydroascorbate + 1,1-dimethylbenzylalcohol + H2O | - |
? | |
L-ascorbic acid + tert-butylhydroperoxide | - |
Euglena gracilis | dehydroascorbate + tert-butylalcohol | - |
? | |
additional information | the activity with glutathione is less than 1.1% of that with L-ascorbic acid, no activity with: cytochrome c, NADH, NADPH, palmitic acid and triose reductone | Euglena gracilis | ? | - |
? | |
NADPH + H2O2 | no activity | Euglena gracilis | ? + H2O | - |
? | |
pyrogallol + H2O2 | 73.1% activity relative to L-ascorbate | Euglena gracilis | 3-hydroxybenzo-1,2-quinone + H2O | - |
? | |
reductic acid + H2O2 | i.e. 2,3-dihydroxy-2-cyclopenten-1-one, 7.1% activity relative to L-ascorbate | Euglena gracilis | ? | - |
? |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
32 | - |
assay at | Euglena gracilis |
32 | 34 | - |
Euglena gracilis |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
maximum activity maintained up to | Euglena gracilis |
40 | - |
inactivated after 5 min | Euglena gracilis |
40 | - |
preincubated in 30% sucrose and 0.05 mM ferrous sulfate, retains 88.1% activity after 5 min | Euglena gracilis |
52 | - |
complete inactivation | Euglena gracilis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
6.2 | - |
- |
Euglena gracilis |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
6 | 7.9 | maximum activity maintained | Euglena gracilis |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
heme | - |
Euglena gracilis |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0018 | - |
KCN | competitive inhibition against H2O2 | Euglena gracilis | |
0.0083 | - |
KCN | uncompetitive inhibition against L-ascorbic acid | Euglena gracilis | |
0.059 | - |
NaN3 | uncompetitive inhibition against H2O2 | Euglena gracilis | |
0.085 | - |
NaN3 | competitive inhibition against L-ascorbic acid | Euglena gracilis |