From Wikipedia, the free encyclopedia
Jump to: navigation, search
Cytochrome P450, family 2, subfamily B, polypeptide 6
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols CYP2B6 ; CPB6; CYP2B; CYP2B7; CYP2B7P; CYPIIB6; EFVM; IIB1; P450
External IDs OMIM123930 MGI88598 HomoloGene73894 IUPHAR: 1324 ChEMBL: 4729 GeneCards: CYP2B6 Gene
EC number
Species Human Mouse
Entrez 1555 13088
Ensembl ENSG00000197408 ENSMUSG00000030483
UniProt P20813 Q9WUD0
RefSeq (mRNA) NM_000767 NM_009999
RefSeq (protein) NP_000758 NP_034129
Location (UCSC) Chr 19:
40.99 – 41.02 Mb
Chr 7:
25.9 – 25.93 Mb
PubMed search [1] [2]

Cytochrome P450 2B6 is an enzyme that in humans is encoded by the CYP2B6 gene.[1] CYP2B6 is a member of the Cytochrome P450 group of enzymes. Along with CYP2A6, it is involved with metabolizing nicotine, along with many other substances.[1]


This gene, CYP2B6, encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by phenobarbital. The enzyme is known to metabolize some xenobiotics, such as the anti-cancer drugs cyclophosphamide and ifosphamide.[1]


Transcript variants for this gene have been described; however, it has not been resolved whether these transcripts are in fact produced by this gene or by a closely related pseudogene, CYP2B7. Both the gene and the pseudogene are located in the middle of a CYP2A pseudogene found in a large cluster of cytochrome P450 genes from the CYP2A, CYP2B and CYP2F subfamilies on chromosome 19q.[1]

CYP2B6 Ligands[edit]

Following is a table of selected substrates, inducers and inhibitors of CYP2B6.

Inhibitors of CYP2B6 can be classified by their potency, such as:

  • Strong inhibitor being one that causes at least a 5-fold increase in the plasma AUC values, or more than 80% decrease in clearance.[2]
  • Moderate inhibitor being one that causes at least a 2-fold increase in the plasma AUC values, or 50-80% decrease in clearance.[2]
  • Weak inhibitor being one that causes at least a 1.25-fold but less than 2-fold increase in the plasma AUC values, or 20-50% decrease in clearance.[2]
Substrates Inhibitors Inducers
Orphenadrine[3][6] (first-generation antihistamine)

Unspecified potency


  1. ^ a b c d "Entrez Gene: cytochrome P450". 
  2. ^ a b c d e f g h i j k l m n Flockhart DA (2007). "Drug Interactions: Cytochrome P450 Drug Interaction Table". Indiana University School of Medicine.  Retrieved on December 25, 2008.
  3. ^ a b c d e f g h i j k l Swedish environmental classification of pharmaceuticals - FASS (drug catalog) - Facts for prescribers (Fakta för förskrivare). Retrieved July 2011
  4. ^ Obach RS, Cox LM, Tremaine LM (2005). "Sertraline is metabolized by multiple cytochrome P450 enzymes, monoamine oxidases, and glucuronyl transferases in human: an in vitro study". Drug Metab. Dispos. 33 (2): 262–70. doi:10.1124/dmd.104.002428. PMID 15547048. 
  5. ^ Meyer MR, Bach M, Welter J, Bovens M, Turcant A, Maurer HH (2013). "Ketamine-derived designer drug methoxetamine: metabolism including isoenzyme kinetics and toxicological detectability using GC-MS and LC-(HR-)MSn". Anal Bioanal Chem 405 (19): 6307–21. doi:10.1007/s00216-013-7051-6. PMID 23774830. 
  6. ^ Guo Z, Raeissi S, White RB, Stevens JC (1997). "Orphenadrine and methimazole inhibit multiple cytochrome P450 enzymes in human liver microsomes". Drug Metab. Dispos. 25 (3): 390–3. PMID 9172960. 
  7. ^ Volak LP, Ghirmai S, Cashman JR, Court MH (August 2008). "Curcuminoids inhibit multiple human cytochromes P450, UDP-glucuronosyltransferase, and sulfotransferase enzymes, whereas piperine is a relatively selective CYP3A4 inhibitor". Drug Metab. Dispos. 36 (8): 1594–605. doi:10.1124/dmd.108.020552. PMC 2574793. PMID 18480186. 

Further reading[edit]

External links[edit]

This article incorporates text from the United States National Library of Medicine, which is in the public domain.