cholesterol 24-hydroxylase; CH24H; cytochrome P450 46A1 (CYP46A1, CYP46)

Function

• role in the turnover of cholesterol
• converts cholesterol into 24S-hydroxycholesterol &, to a lesser extent, 25-hydroxycholesterol

  cholesterol + NADPH + O2
             <-->
  (24S)-24-hydroxycholesterol + NADP+ + H2O

Cofactor: heme group (putative)

Kinetic parameters:

• KM=2.2 uM for 24(S)-hydroxycholesterol

Structure

belongs to the cytochrome P450 family

Compartment

• endoplasmic reticulum membrane
• microsome membrane
• single-pass membrane protein

Expression

• expressed in brain
• mRNA broadly distributed with higher levels in gray matter & lower levels in regions rich in white matter
• not detected in fetal sample but its expression increases linearly with age

More general terms

• cytochrome P450

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=10858
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:10858
• OMIM: https://mirror.omim.org/entry/604087
• UniProt: http://www.uniprot.org/uniprot/Q9Y6A2.html