Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Hydroxyurea | 26% inhibition at 1 mM | Helicoverpa zea | |
KCN | 10% inhibition at 5 mM | Helicoverpa zea | |
p-Aminophenol | not inhibitory | Helicoverpa zea |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.12 | - |
H2O2 | - |
Helicoverpa zea | |
0.14 | - |
ascorbate | - |
Helicoverpa zea |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
10000 | - |
partially purified enzyme, molecular weight cut-off centrifugation | Helicoverpa zea |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-ascorbate + H2O2 | Helicoverpa zea | the enzyme may be important in removing H2O2 and lipid peroxides in insects | dehydroascorbate + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Helicoverpa zea | - |
larvae | - |
Purification (Comment) | Organism |
---|---|
partial, from whole body homogenate, using ammonium sulfate fractionation, column chromatography on Sephadex G-75 and isoelectric focusing. Second isolation of the enzyme: from regurgitant of actively feeding fifth instar organism, using centrifugation, a concentrator and isoelectric focusing | Helicoverpa zea |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
fat body | 55.6% relative activity to salivary gland | Helicoverpa zea | - |
malpighian tubule | 31.1% relative activity to salivary gland | Helicoverpa zea | - |
midgut | 20% relative activity to salivary gland | Helicoverpa zea | - |
salivary gland | highest activity | Helicoverpa zea | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
7.1 | - |
substrate: cumene hydroperoxide | Helicoverpa zea |
19.2 | - |
substrate: tert-butyl hydroperoxide | Helicoverpa zea |
20.9 | - |
substrate: H2O2 | Helicoverpa zea |
46.7 | - |
partially purified enzyme | Helicoverpa zea |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
cysteine + H2O2 | enzyme partially purified from whole body homogenate, 40% of the activity with L-ascorbate | Helicoverpa zea | ? + H2O | - |
? | |
cytochrome c + H2O2 | enzyme partially purified from whole body homogenate, 44% of the activity with L-ascorbate | Helicoverpa zea | ? + H2O | - |
? | |
glutathione + H2O2 | enzyme partially purified from whole body homogenate: 22% of the activity with L-ascorbate, enzyme partially purified from regurgitant: 0% relative activity to L-ascorbate, when assayed at the same concentration | Helicoverpa zea | ? + H2O | - |
? | |
guaiacol + H2O2 | no activity | Helicoverpa zea | ? | - |
? | |
L-ascorbate + H2O2 | tert-butyl hydroperoxide and cumene hydroperoxide also serve as electron acceptor | Helicoverpa zea | dehydroascorbate + H2O | - |
? | |
L-ascorbate + H2O2 | L-ascorbate is the most effective natural electron donor | Helicoverpa zea | dehydroascorbate + H2O | - |
? | |
L-ascorbate + H2O2 | the enzyme may be important in removing H2O2 and lipid peroxides in insects | Helicoverpa zea | dehydroascorbate + 2 H2O | - |
? | |
L-ascorbic acid + cumene hydroperoxide | 34% of the activity with H2O2 | Helicoverpa zea | dehydroascorbate + 1,1-dimethylbenzylalcohol + H2O | - |
? | |
L-ascorbic acid + tert-butylhydroperoxide | 92% of the activity with H2O2 | Helicoverpa zea | dehydroascorbate + tert-butylalcohol | - |
? | |
additional information | no activity with guaiacol | Helicoverpa zea | ? | - |
? | |
NADPH + H2O2 | enzyme partially purified from whole body homogenate: 93% of the activity with L-ascorbate, enzyme partially purified from regurgitant: 36% of the activity with L-ascorbate, when assayed at the same concentration | Helicoverpa zea | ? + H2O | - |
? |
Subunits | Comment | Organism |
---|---|---|
monomer | 1 * 10000, SDS-PAGE, partially purified enzyme | Helicoverpa zea |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
100 | - |
complete loss of activity | Helicoverpa zea |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Helicoverpa zea |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
additional information | the enzyme may not be a heme-peroxidase | Helicoverpa zea |