Lanosterol Demethylase
| Lanosterol Demethylase | ||
|---|---|---|
|
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| Ribbon model of the human CYP51A1 with heme (green) and ketoconazole ala calottes , according to PDB 3LD6 | ||
| Properties of human protein | ||
| Mass / length primary structure | 503 amino acids | |
| Cofactor | Hamm | |
| Isoforms | 1, 2 | |
| Identifier | ||
| Gene name | CYP51A1 | |
| External IDs | ||
| Enzyme classification | ||
| EC, category | 1.14.13.70 , monooxygenase | |
| Response type | repeated oxidation with splitting off | |
| Substrate | 14-methyl steroid + 3 O 2 + 3 NADPH | |
| Products | 14-demethyl steroid + formate + 4 H 2 O + 3 NADP + | |
| Occurrence | ||
| Parent taxon | Eukaryotes , some bacteria | |
The enzyme lanosterol demethylase (also: CYP51A1 ) catalyzes the dehydrogenative demethylation of lanosterol to 4,4-dimethyl-5α-cholesta-8,14,24-trien-3β-ol . This chemical reaction is an intermediate step in cholesterol and ergosterol biosynthesis , which takes place in eukaryotes , but also in some bacteria . It is a monooxygenase of the cytochrome P450 type, i.e. with heme as a cofactor . CYP51A1 is produced by humans in many tissue types .
Catalyzed reaction
+ 3 O 2 + 3 NADPH + formate + 4 H 2 O + 3 NADP +
In several oxidation steps, the 14-methyl group of the lanosterol is removed and a 14,15 double bond is created, with formate being split off. Other 14-methyl steroids (eburicol, norlanosterol, obtusifoliol) are also accepted as substrates.
Individual evidence
Web links
Wikibooks: Cholesterol Biosynthesis - Learning and Teaching Materials
