Cloned (Comment) | Organism |
---|---|
expression in Escherichia coli | Aspergillus nidulans |
Protein Variants | Comment | Organism |
---|---|---|
H1004A | mutant enzyme with abolished 8-hydroperoxide isomerase activity, whereas dioxygenase activity is still present | Aspergillus nidulans |
Y374 | the mutant enzyme shows no detectable activity when incubated with (9Z,12Z)-octadeca-9,12-dienoate as a substrate. When incubated with the intermediate product (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate it is able to catalyze isomerization to (5S,8R,9Z,12Z)-5,8-dihydroperoxy-9,12-octadecadienoate | Aspergillus nidulans |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | suicide inactivation, activity falls to zero within a few min although substrates were available in sufficient amounts | Aspergillus nidulans |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.005 | - |
palmitoleate | pH 7.2, 24°C | Aspergillus nidulans | |
0.00671 | - |
oleate | pH 7.2, 24°C | Aspergillus nidulans | |
0.0183 | - |
linoleate | pH 7.2, 24°C | Aspergillus nidulans | |
0.0226 | - |
(11Z)-icos-11-enoic acid | pH 7.2, 24°C | Aspergillus nidulans |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
110000 | - |
4 * 110000, SDS-PAGE | Aspergillus nidulans |
440000 | - |
gel filtration | Aspergillus nidulans |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
linoleate + O2 | Aspergillus nidulans | the enzyme is involved in the regulation of the life cycle of Aspergillus nidulans. Synthesis of the psi factor (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate, that influences the development of the asexual conidiophores and sexual cleistothecia | (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Aspergillus nidulans | Q6RET3 | - |
- |
Purification (Comment) | Organism |
---|---|
- |
Aspergillus nidulans |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
3.2 | - |
pH 7.2, 24°C | Aspergillus nidulans |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
(11Z)-icos-11-enoic acid + O2 | - |
Aspergillus nidulans | 10-hydroperoxyeicosenoic acid | - |
? | |
(11Z,14Z)-icosa-11,14-dienoic acid + O2 | - |
Aspergillus nidulans | (11Z,14Z)-10-hydroperoxyeicosa-11,14-dienoic acid | - |
? | |
(11Z,14Z,17Z)-icosa-11,14,17-trienoic acid + O2 | - |
Aspergillus nidulans | (11Z,14Z,17Z)-10-hydroperoxyeicosa-11,14,17-trienoic acid | - |
? | |
linoleate + O2 | the enzyme is involved in the regulation of the life cycle of Aspergillus nidulans. Synthesis of the psi factor (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate, that influences the development of the asexual conidiophores and sexual cleistothecia | Aspergillus nidulans | (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate | - |
? | |
linoleate + O2 | i.e. (9Z,12Z)-octadeca-9,12-dienoate. The N-terminal heme peroxidase domain might be responsible for the dioxygenase reaction as the first step of the PpoA reaction, i.e. oxidation of linoleic acid to (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate as an intermediate product. The C-terminal P450 domain catalyzes the second reaction step, the isomerization of (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate to (5S,8R,9Z,12Z)-5,8-dihydroperoxy-9,12-octadecadienoate, and is therefore termed the 8-hydroperoxide isomerase P450 domain | Aspergillus nidulans | (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate | - |
? | |
oleate + O2 | - |
Aspergillus nidulans | (9Z)-8-hydroperoxyoctadec-9-enoate | - |
? | |
palmitoleate + O2 | - |
Aspergillus nidulans | (9Z)-8-hydroperoxyhexadec-9-enoate | - |
? |
Subunits | Comment | Organism |
---|---|---|
tetramer | 4 * 110000, SDS-PAGE | Aspergillus nidulans |
Synonyms | Comment | Organism |
---|---|---|
PpoA | - |
Aspergillus nidulans |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
24 | - |
assay at | Aspergillus nidulans |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
3.5 | - |
palmitoleate | pH 7.2, 24°C | Aspergillus nidulans | |
4.95 | - |
oleate | pH 7.2, 24°C | Aspergillus nidulans | |
5.9 | - |
(11Z)-icos-11-enoic acid | pH 7.2, 24°C | Aspergillus nidulans | |
6.3 | - |
linoleate | pH 7.2, 24°C | Aspergillus nidulans |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.2 | - |
assay at | Aspergillus nidulans |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
cytochrome P450 | PpoA contains a high spin ferriheme. PpoA uses different heme domains to catalyze two separate reactions. Within the N-terminal heme peroxidase domain, linoleic acid is oxidized to (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate by abstracting a H-atom from C-8 of the fatty acid, yielding a carbon-centered radical that reacts with molecular dioxygen. In the second reaction step, (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate is isomerized within the C-terminal P450 heme thiolate domain to (5S,8R,9Z,12Z)-5,8-dihydroxy-9,12-octadecadienoate | Aspergillus nidulans | |
heme | PpoA contains a high spin ferriheme. PpoA uses different heme domains to catalyze two separate reactions. Within the N-terminal heme peroxidase domain, linoleic acid is oxidized to (8R)-hydroperoxyoctadecadienoic acid by abstracting a H-atom from C-8 of the fatty acid, yielding a carbon-centered radical that reacts with molecular dioxygen. In the second reaction step, 8-hydroperoxyoctadecadienoic acid is isomerized within the C-terminal P450 heme thiolate domain to 5,8-dihydroxyoctadecadienoic acid | Aspergillus nidulans |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
261 | - |
(11Z)-icos-11-enoic acid | pH 7.2, 24°C | Aspergillus nidulans | |
344 | - |
linoleate | pH 7.2, 24°C | Aspergillus nidulans | |
700 | - |
palmitoleate | pH 7.2, 24°C | Aspergillus nidulans | |
738 | - |
oleate | pH 7.2, 24°C | Aspergillus nidulans |