Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Phospholipid | inclusion of P-450 into vesicles | Bos taurus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
adrenodoxin | oxidized form, high affinity to P-450scc, inhibits side chain cleavage by competition with reduced form | Bos taurus | |
Ca2+ | CaCl2 inhibits side chain cleavage activity at 100 mM NaCl, 50% inhibition with 0.07 mM in Tween 20 and 0.03 mM for vesicle-incorporated, Ca2+ does not affect binding of either cholesterol of oxidized adrenodoxin to P-450scc | 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 | - |
mitochondrial inner membrane | integral to membrane | Bos taurus | 5743 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Ca2+ | ineffective activator | Bos taurus | |
Ca2+ | particulary but also other metal ions modulate adrenodoxin binding to adrenodoxin reductase and P-450, therefore activation of cholesterol side chain cleavage and adrenodoxin reduction | Bos taurus | |
Mg2+ | increased MgCl2 concentrations continue to increase side chain cleavage activity even after all adrenodoxin is reduced | Bos taurus | |
additional information | increase of side chain cleavage activity from 50 to 100 mM NaCl, higher concentrations cause a decrease, total loss at 300 mM | Bos taurus |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bos taurus | - |
- |
- |
Purification (Comment) | Organism |
---|---|
DEAE-cellulose, adrenodoxin-Sepharose | Bos taurus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
adrenal cortex | - |
Bos taurus | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
cholesterol + reduced adrenodoxin + O2 | - |
Bos taurus | pregnenolone + 4-methylpentanal + oxidized adrenodoxin + H2O | - |
? | |
additional information | cholesterol side chain cleavage activity is dependent on free reduced adrenodoxin | Bos taurus | ? | - |
? | |
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 |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.2 | - |
assay at | Bos taurus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
adrenodoxin | transports electrons from adrenodoxin reductase to cytochrome P-450 by shuttling | Bos taurus | |
NADPH | NADPH-linked adrenodoxin reductase | Bos taurus |