Contents

Search

cytochrome P450

The cytochrome P450 enzyme family is the major phase 1 enzyme of drug metabolism. It evolutionary origin is > 3.5 billion years. Cyt P450 enzymes are heme-containing membrane proteins localized to the smooth endoplasmic reticulum of numerous tissues. Cyt P450 is closely associated with cyt P450 reductase (a membrane- associated flavoprotein) in a ratio of 10 cyt P450 to one reductase. Cyt P450 reductase reduces Fe+3 of the cyt P450 heme to Fe+2 which binds molecular oxygen (O2) for monooxygenation (hydroxylation) of substrate (steroid, xenobiotic or drug). See phase 1 enzyme for the roles of cyt P450 in drug metabolism. Laboratory: - cytochrome P450 genotyping

Related

NADPH dependent cytochrome P450 reductase (CPR, P450R, POR, CYPOR) phase 1 drug metabolizing enzyme

Specific

25-hydroxyvitamin D-1 alpha hydroxylase, mitochondrial; cytochrome P450 subfamily XXVIIB polypeptide 1; cytochrome p450 27B1; calcidiol 1-monooxygenase; 25-OHD-1 alpha-hydroxylase; 25-hydroxyvitamin D(3) 1-alpha-hydroxylase; VD3 1A hydroxylase; P450C1 alpha; P450VD1-alpha (CYP27B1, CYP1ALPHA, CYP27B) cholesterol 24-hydroxylase; CH24H; cytochrome P450 46A1 (CYP46A1, CYP46) cytochrome P450 11A1 (CYP11A1, cholesterol 20,22 desmolase, cytochrome P450 SCC, CYP11A1) cytochrome P450 11B (steroid-11-beta hydroxylase) cytochrome P450 17A1; cytochrome P450 C17; steroid-17-alpha hydroxylase; steroid 17-alpha-hydroxylase/17,20 lyase; CYPXVII; P450-C17; P450c17; steroid 17-alpha-monooxygenase (CYP17A1, CYP17, S17AH) cytochrome P450 19A1 (aromatase, estrogen synthetase, CYP19A1) cytochrome P450 1A (CYP1A) cytochrome P450 1B1 (dioxin-inducible cytochrome P450, CYPIB1) cytochrome P450 20A1 (CYP20A1) cytochrome P450 21A2; cytochrome P450 21; steroid-21-beta-hydroxylase (CYP21A2, CYP21B) cytochrome P450 24A1; 1,25-dihydroxyvitamin D3 24-hydroxylase, mitochondrial; vitamin D3 24-hydroxylase; 24-OHase; P450-CC24 (CYP24A1, CYP24) cytochrome P450 26A1 (retinoic acid-metabolizing cytochrome, P450RAI, retinoic acid 4-hydroxylase, cytochrome p450 subfamily 26A polypeptide 1) cytochrome P450 26A2 (CYP26A2, CYP26B1, retinoic acid-metabolizing cytochrome, cytochrome p450 subfamily 26A polypeptide 2) cytochrome P450 26C1 cytochrome P450 27A1; sterol 26-hydroxylase; sterol 27-hydroxylase; vitamin D3 25-hydroxylase; 5-beta cholestane-3-alpha,7-alpha,12-alpha-triol 27 hydroxylase cytochrome P450 27B1 cytochrome P450 27C1 (CYP27C1) cytochrome P450 2A (CYP2A) cytochrome P450 2B (CYP2B) cytochrome P450 2C (CYP2C) cytochrome P450 2D6 (cytochrome P450 2D, cytochrome P450 DB1, debrisoquine-4-hydroxylase, CYP2D6) cytochrome P450 2E1 (ethanol-inducible cytochrome P450, CYP2E1) cytochrome P450 2F1 (CYP2F1) cytochrome P450 2G1 (CYP2G1) cytochrome P450 2G1-like protein; cyt P450 2G1L (CYP2G1L, CYP2G1P) cytochrome P450 2G2 (CYP2G2) cytochrome P450 2J2 (arachidonic acid epoxygenase, CYP2J2) cytochrome P450 2R1 (vitamin D 25-hydroxylase, CYP2R1) cytochrome P450 2S1 (CYP2S1) cytochrome P450 2U1 (CYP2U1) cytochrome P450 2W1 (CYP2W1) cytochrome P450 39A1 (CYP39A1, oxysterol 7-alpha-hydroxylase) cytochrome P450 3A (CYP3A) cytochrome P450 4A11 (fatty acid omega-hydroxylase, P-450 HK omega, lauric acid omega-hydroxylase, CYP4A11, P450-HL-omega) cytochrome P450 4A22 (CYPIVA22, fatty acid omega-hydroxylase, Lauric acid omega-hydroxylase, CYP4A22) cytochrome P450 4B1 (P450-HP, CYP4B1) cytochrome P450 4F11 (CYP4F11) cytochrome P450 4F12 (CYP4F12) cytochrome P450 4F2 (leukotriene-B4 omega-hydroxylase, leukotriene-B4 20-monooxygenase, cytochrome P450-LTB-omega, CYP4F2) cytochrome P450 4F22 (CYP4F22) cytochrome P450 4F3 (LTB4 20-monooxygenase, LTB4 omega-hydroxylase, cytochrome P450 LTB4-omega, CYP4F3) cytochrome P450 4F8 (CYP4F8) cytochrome P450 4V2 (CYP4V2) cytochrome P450 4X1 (CYP4X1) cytochrome P450 4Z1 (CYP4Z1) cytochrome P450 51; sterol 14-alpha demethylase; lanosterol 14-alpha demethylase (CYPL1, P450L1, LDM, P450-14DM) cytochrome p450 5A; thromboxane A [TxA] synthase 1 (TBXAS1, CYP5, CYP5A1) cytochrome P450 7A1 (CYP7A1, cholesterol-7-alpha-hydroxylase, cholesterol 7-alpha-monooxygenase) cytochrome P450 7B1 (CYP7B1, oxysterol 7-alpha-hydroxylase) cytochrome P450 8B1 (CYP8B1, sterol 12-alpha-hydroxylase, 7 alpha-hydroxy-4-cholesten-3-one 12-alpha-hydroxylase) steroid-6-hydroxylase or corticosterone-6-hydroxylase

General

cytochrome flavoprotein hydroxylase; monooxygenase membrane protein

Properties

COMPARTMENT: smooth endoplasmic reticulum MOTIF: membrane region heme-binding site [cysteine residue] COFACTOR-BOUND: heme

References

  1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996 pg 12
  2. Cytochrome P450 Drug-Interaction Table http://medicine.iupui.edu/flockhart/table.htm
  3. Cytochrome P-450 Drug Interactions Prescriber's Letter 6(4): 1999 Detail-Document#: 150400 (subscription needed) http://www.prescribersletter.com
  4. Prescriber's Letter 17(1): 2010 Cytochrome P450 Drug Interactions CHART: Cytochrome P450 Drug Interactions COMMENTARY: Proton Pump Inhibitor and Plavix Interaction: An Update Detail-Document#: 260112 (subscription needed) http://www.prescribersletter.com
  5. Prescriber's Letter 17(6): 2010 Cytochrome P450 Drug Interactions Detail-Document#: 260623 (subscription needed) http://www.prescribersletter.com