Cytochrome b5 reductase
| cytochrome-b5 reductase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 | |||||||||
| Identifiers | |||||||||
| EC no. | 1.6.2.2 | ||||||||
| CAS no. | 9032-25-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
| Cytochrome b5 reductase | |
|---|---|
| Identifiers | |
| Symbol | CYB5R |
| InterPro | IPR001834 |
| Membranome | 421 |
Cytochrome-b5 reductase is a NADH-dependent enzyme that converts ferricytochrome from a Fe3+ form to a Fe2+ form.[1] It contains FAD and catalyzes the reaction:
NADH + H+ + 2 ferricytochrome b5 = NAD+ + 2 ferrocytochrome b5
In its b5-reducing capacity, this enzyme is involved in desaturation and elongation of fatty acids, cholesterol biosynthesis, and drug metabolism.
This enzyme can also reduce methemoglobin to normal hemoglobin, gaining it the inaccurate synonym methemoglobin reductase. Isoforms expressed in erythrocytes (CYB5R1, CYB5R3) perform this function in vivo. Ferricyanide is another substrate in vitro.[citation needed]
The following four human genes encode cytochrome-b5 reductases:[citation needed]
See also
References
- ^ Tamura M, Yubisui T, Takeshita M, Kawabata S, Miyata T, Iwanaga S (May 1987). "Structural comparison of bovine erythrocyte, brain, and liver NADH-cytochrome b5 reductase by HPLC mapping". Journal of Biochemistry. 101 (5): 1147–59. doi:10.1093/oxfordjournals.jbchem.a121979. PMID 3654589.
External links
- Cytochrome-B(5)+Reductase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
