CYP8B1
CYP8B1 (cytochrome P450 family 8 subfamily B member 1, also known as CYP12) is an endoplasmic reticulum monooxygenase and sterol 12-alpha-hydroxylase. It acts in primary bile acid biosynthesis and sets the balance between cholic acid and chenodeoxycholic acid. Browse Assay Genie's current range of CYP8B1 research reagents below, or read on for the biology behind the target.
CYP8B1, formally 7-alpha-hydroxycholest-4-en-3-one 12-alpha-hydroxylase, catalyses the 12alpha-hydroxylation of key intermediates in the classic pathway of primary bile acid biosynthesis. Its substrates include 7alpha-hydroxycholest-4-en-3-one, 3alpha,7alpha-dihydroxy-5beta-cholestan-26-oate and chenodeoxycholate, and it may also hydroxylate 5beta-cholestane-3alpha,7alpha-diol. The best-described reaction converts 7 alpha-hydroxy-4-cholesten-3-one into 7-alpha,12-alpha-dihydroxy-4-cholesten-3-one.
As a monooxygenase, the enzyme inserts one atom of molecular oxygen into its substrate and reduces the second to water. The electrons come from NADPH through cytochrome P450 reductase (CPR). By controlling the biliary balance of cholic acid and chenodeoxycholic acid, CYP8B1 regulates the intestinal absorption of dietary lipids. This balance also affects the solubility of cholesterol in bile, since both bile acids are secreted into it.
The CYP8B1 gene belongs to the cytochrome P450 superfamily, whose members are monooxygenases involved in drug metabolism and in the synthesis of cholesterol, steroids and other lipids. The protein is a membrane protein of the endoplasmic reticulum and microsomes. The CYP8B1 gene is unique among cytochrome P450 genes because it is intronless. Earlier names include cytochrome P450, subfamily VIIIB (sterol 12-alpha-hydroxylase), polypeptide 1, and the symbol CYP12. HGNC places it in the cytochrome P450 family 8 gene group, and the mouse ortholog is Cyp8b1.
CYP8B1 catalyses 12alpha-hydroxylation of intermediates in the classic pathway, making it a key enzyme for studying primary bile acid synthesis.
The enzyme determines the relative amounts of cholic acid and chenodeoxycholic acid secreted in bile, a central question in bile composition research.
By shaping the biliary bile acid profile, CYP8B1 regulates intestinal absorption of dietary lipids.
As a CPR-dependent monooxygenase and an intronless P450 gene, CYP8B1 is a useful model for P450 sterol metabolism and gene structure.
CYP8B1 is a sterol 12-alpha-hydroxylase in the classic pathway of primary bile acid biosynthesis. It hydroxylates intermediates such as 7alpha-hydroxycholest-4-en-3-one, using oxygen and NADPH-derived electrons from cytochrome P450 reductase, and so controls the cholic acid to chenodeoxycholic acid balance.
CYP8B1 is also called CYP12 and 7-alpha-hydroxycholest-4-en-3-one 12-alpha-hydroxylase. Older HGNC names describe it as cytochrome P450, subfamily VIIIB (sterol 12-alpha-hydroxylase), polypeptide 1, or cytochrome P450, family 8, subfamily B, polypeptide 1.
A mouse ortholog, Cyp8b1, is recorded for the human CYP8B1 gene. The human gene is notable as an intronless member of the cytochrome P450 superfamily. Check the datasheet of any product for its validated reactivity.
Other cytochrome P450 enzymes involved in sterol, steroid and lipid metabolism.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q9UNU6; product specifications from Assay Genie datasheets.