General Stability | Organism |
---|---|
loss of activity after incubation of crude extracts from pea shoots with either pronase or chymotrypsin | Pisum sativum |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
2-mercaptoethanol | enzyme form C: 50% inhibition at 5 mM, 6 min, 100% inhibition after 18 min | Pisum sativum | |
dithiothreitol | enzyme form C: 100% inhibition at 0.1 mM for 5 min, 57% of the inhibition can be recovered by filtration on Sephadex G-25 and a further 14% is recovered after the addition of homocystine at 2 mM | Pisum sativum | |
KCN | enzyme form C: 74% inhibition at 0.1 mM | Pisum sativum | |
NaN3 | enzyme form C: 27% inhibition at 5 mM | Pisum sativum | |
reduced glutathione | enzyme form C: 75% inhibition at 0.25 mM for 10 min | Pisum sativum |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | both forms of the enzyme show a very high affinity for H2O2, Km values below 0.005 | Pisum sativum | |
2.9 | - |
ascorbate | enzyme form C | Pisum sativum | |
6.5 | - |
ascorbate | enzyme form B | Pisum sativum | |
7.4 | - |
guaiacol | enzyme form C | Pisum sativum |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe | hemoprotein | Pisum sativum |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
57000 | - |
crude pea shoot extract, gel filtration, co-elution of two forms of the enzyme, B and C, which can be separated by cation-exchange chromatography | Pisum sativum |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-ascorbate + H2O2 | Pisum sativum | physiological role of the enzyme: removal of H2O2, prevention of H2O2 accumulation | dehydroascorbate + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pisum sativum | - |
pea | - |
Pisum sativum | - |
var. Kleine Rheinlaenderin | - |
Purification (Comment) | Organism |
---|---|
using Ca-phosphate gel treatment, ammonium sulfate fractionation, column chromatography on Sephadex G-100, ultrafiltration and column chromatography on DEAE-Sephadex and CM-Sephadex C-50, two forms of the enzyme, B and C, can be separated by the CM-Sephadex C-50 step | Pisum sativum |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
shoot | - |
Pisum sativum | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
guaiacol + H2O2 | form C enzyme, only onesixteenth the rate observed with L-ascorbate | Pisum sativum | ? | - |
? | |
L-ascorbate + H2O2 | - |
Pisum sativum | dehydroascorbate + H2O | - |
? | |
L-ascorbate + H2O2 | physiological role of the enzyme: removal of H2O2, prevention of H2O2 accumulation | Pisum sativum | dehydroascorbate + 2 H2O | - |
? |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
70 | - |
5 min, complete inactivation | Pisum sativum |
100 | - |
10 min, loss of activity | Pisum sativum |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5.2 | - |
enzyme form B | Pisum sativum |
6.2 | - |
enzyme form C | Pisum sativum |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
5 | 8 | both forms of the enzyme | Pisum sativum |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
heme | - |
Pisum sativum |