Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Phospholipid | cholesterol gains access to the cytochrome within micelles | Bos taurus | |
Tween 20 | small stabilizing and binding activating effect on ternary complex of adrenodoxin-cholesterol-P-450scc | Bos taurus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Ca2+ | inhibits side chain cleavage activity optimally activated by 100 mM NaCl | Bos taurus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0012 | - |
reduced adrenodoxin | - |
Bos taurus | |
0.39 | - |
cholesterol | - |
Bos taurus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrial inner membrane | adrenodoxin reductase and adrenodoxin are peripheral proteins on matrix side of inner membrane, P-450scc is integral membrane protein | Bos taurus | 5743 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Ca2+ | very little | Bos taurus | |
Mg2+ | - |
Bos taurus | |
additional information | Kd for adrenodoxin increases with increase of ions from NaCl, binding of adrenodoxin to P-450scc is more sensitive to changes in metal ion concentration than cholesterol binding, high salt concentrations cause fall-off in activity | Bos taurus |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bos taurus | - |
- |
- |
Purification (Comment) | Organism |
---|---|
ammonium sulfate fractioning, aniline-Sepharose, adrenodoxin-Separose | Bos taurus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
adrenal cortex | - |
Bos taurus | - |
Storage Stability | Organism |
---|---|
-70°C, mitochondrial pellet, 30-40 mg/ml, 100 mM potassium phosphate, pH 7.3, 0.2 mM EDTA | Bos taurus |
4°C, purified, 50 mM potassium phosphate, pH 7.3, 0.1 mM dithiothreitol, 10% glycerol, stable a few weeks | Bos taurus |
purified, 25 mM potassium phosphate, pH 7.3, 0.05 mM EDTA, 0.05 mM dithiothreitol, 0.025 mM deoxycorticosterone, 0.25% Tween 20, 0.25% sodium cholate | Bos taurus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
cholesterol + reduced adrenodoxin + O2 | - |
Bos taurus | pregnenolone + 4-methylpentanal + oxidized adrenodoxin + H2O | - |
? | |
cholesterol + reduced adrenodoxin + O2 + H+ | - |
Bos taurus | pregnenolone + 4-methylpentanal + oxidized adrenodoxin + H2O | - |
r | |
additional information | suggested shuttle mechanism in which adrenodoxin transfers electrons between adrenodoxin reductase and cytochrome P-450. No ternary adrenodoxin-adrenodoxin reductase-P-450 complex | Bos taurus | ? | - |
? | |
additional information | dissociation of oxidized adrenodoxin from P-450scc must be a potential rate-limiting factor | Bos taurus | ? | - |
? |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Bos taurus |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
additional information | - |
increase of complex formation of adrenodoxin and cytochrome P-450scc in absence of cholesterol with decrease of temperature to 6°C, elevated temperature decreases the affinity of P-450scc for cholesterol | Bos taurus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
adrenodoxin | transports electrons from adrenodoxin reductase to cytochrome P-450 by shuttling | Bos taurus | |
heme | - |
Bos taurus | |
NADPH | NADPH-linked adrenodoxin reductase | Bos taurus |