25-Hydroxyvitamin D 1-alpha-hydroxylase
Mammalian protein found in humans
From Wikipedia, the free encyclopedia
25-Hydroxyvitamin D 1-alpha-hydroxylase (VD 1A hydroxylase) also known as calcidiol 1-monooxygenase[citation needed] or cytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a cytochrome P450 enzyme that in humans is encoded by the CYP27B1 gene.[5][6][7]
| calcidiol 1-monooxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.14.15.18 | ||||||||
| CAS no. | 9081-36-1 | ||||||||
| 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 | ||||||||
| |||||||||
VD 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin (keratinocytes), immune cells,[8] and bone (osteoblasts).[9]
Reactions
The enzyme catalyzes the hydroxylation of calcifediol to calcitriol (the bioactive form of Vitamin D):[10]
- calcidiol + 2 reduced adrenodoxin + 2 H+ + O2 ⇌ calcitriol + 2 oxidized adrenodoxin + H2O
The enzyme is also able to oxidize ercalcidiol (25-OH D2) to ercalcitriol, secalciferol to calcitetrol, and 25-hydroxy-24-oxocalciol to (1S)-1,25-dihydroxy-24-oxocalciol.[11]
Clinical significance
Loss-of-function mutations in CYP27B1 cause Vitamin D-dependent rickets, type IA.[12]
Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles. [§ 1]
- The interactive pathway map can be edited at WikiPathways: "VitaminDSynthesis_WP1531".
