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Cytochrome P450

  1. Michael R. Waterman1,
  2. Irina A. Pikuleva2

Published Online: 15 SEP 2006

DOI: 10.1002/3527600906.mcb.200300080

Encyclopedia of Molecular Cell Biology and Molecular Medicine

Encyclopedia of Molecular Cell Biology and Molecular Medicine

How to Cite

Waterman, M. R. and Pikuleva, I. A. 2006. Cytochrome P450. Encyclopedia of Molecular Cell Biology and Molecular Medicine. .

Author Information

  1. 1

    University of Texas Medical Branch, Galveston, Texas, USA

  2. 2

    Vanderbilt University School of Medicine, Nashville, Tennessee, USA

Publication History

  1. Published Online: 15 SEP 2006


In the original issues of this Encyclopedia in 1996, there was the article (Volume 1) on cytochrome P450 monooxygenases. This new article follows the same format as that used previously. However, a great deal of interesting information on P450s has appeared in the last six to seven years. Accordingly, it is the goal of the authors to present the basic principles of the P450 system as outlined in the previous article, while at the same time taking advantage of new discoveries to provide more depth in understanding these fascinating enzymes.

Cytochrome P450 is the generic name applied to a large superfamily of hemoprotein, mixed-function oxidases (monooxygenases) that metabolize a structurally diverse group of exogenous and endogenous organic substrates. The name is derived from the prominent absorption band observed at 450 nm following reduction of the heme iron and its coordination with carbon monoxide. These enzymes are widely distributed among all biological kingdoms and they catalyze a reaction of the general nature

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In the case of exogenous substrates, this reaction is most frequently involved in an organism's effort to detoxify foreign compounds (xenobiotics) from the environment. In the case of endogenous substrates, the reaction is generally involved in the production of biologically more active compounds (viz. steroid hormones) from less active compounds (viz. cholesterol).


  • Endogenous Substrates;
  • Exogenous Substrates;
  • Hemoprotein;
  • Monooxygenase;
  • Superfamily