Inhibitors | Comment | Organism | Structure |
---|---|---|---|
22-Amino-23,24-bisnor-5-cholen-3beta-ol | 22-amine derivative, same steroid ring structure as cholesterol, competitive inhibitor with respect to cholesterol, 50% reversible inhibition at 0.0001 mM, reversible cooperative binding; dual interaction: binding of steroid ring to cholesterol site and bonding of the amine to the heme iron. need not be metabolically activated in order to inhibit the enzyme, not metobolized to pregnenolone. 60% competitive inhibition at 0.00015 mM | Bos taurus | |
22-amino-23,24-bisnor-5alpha-cholen-3beta-ol | 50% inhibition at 0.003 mM | Bos taurus | |
23,24-bisnor-5-cholene-3beta,22-diol | competitive inhibitor, 40% inhibition at 0.01 mM, 50% at 0.015 mM, resembles the intermediate 22-hydroxycholesterol but acts as an inhibitor rather than serving as a substrate | Bos taurus | |
additional information | amine binding to heme is important for tight inhibitor potency rather than the 5-androstene ring, 23,24-bisnor-5-cholen-3beta-ol-22-carboxamide is ineffective as inhibitor, side chain carbons 23-27 may play some role in positioning the substrate for hydroxylation; cholesterol analogues have shortened side chain and primary amine group, tested in presence of 0.07 mM cholesterol | Bos taurus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrial inner membrane | - |
Bos taurus | 5743 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
cholesterol + 6 reduced adrenodoxin + 3 O2 | Bos taurus | - |
pregnenolone + 4-methylpentanal + 6 oxidized adrenodoxin + 4 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bos taurus | - |
- |
- |
Purification (Comment) | Organism |
---|---|
- |
Bos taurus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
adrenal cortex | - |
Bos taurus | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
cholesterol + 6 reduced adrenodoxin + 3 O2 | - |
Bos taurus | pregnenolone + 4-methylpentanal + 6 oxidized adrenodoxin + 4 H2O | - |
? | |
cholesterol + reduced adrenodoxin + O2 | intermediates (22R)-22-hydroxycholesterol and (20R,22R)-20,22-dihydroxycholesterol from hydroxylation | Bos taurus | pregnenolone + 4-methylpentanal + oxidized adrenodoxin + H2O | - |
? | |
cholesterol + reduced adrenodoxin + O2 | hydroxylation of cholesterol at C-22, then C-20, followed by oxidative scission of the glycol to get pregnenolone | Bos taurus | pregnenolone + 4-methylpentanal + oxidized adrenodoxin + H2O | - |
? | |
additional information | only a single active site of enzyme | Bos taurus | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | single band, SDS-PAGE | 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 | promotes cholesterol binding | Bos taurus | |
heme | 3 mixed function oxidation cycles at the single heme center | Bos taurus | |
NADPH | - |
Bos taurus |