Chemicals and Drugs

Cytochrome P-450 Enzyme System

A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.

MeSH Record

Classification

Related Concepts

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MeSH Record

Synonyms

41 entry terms
  • CYP450 Family
  • CYP450 Superfamily
  • Cytochrome P-450
  • Cytochrome P-450 Enzyme
  • Cytochrome P-450 Enzymes
  • Cytochrome P-450 Families
  • Cytochrome P-450 Superfamily
  • Cytochrome P450
  • Cytochrome P450 Superfamily
  • Cytochrome p450 Families
  • P-450 Enzyme
  • P-450 Enzymes
  • P450 Enzyme
  • P450 Enzymes
  • Cytochrome P 450
  • Cytochrome P 450 Enzyme
  • Cytochrome P 450 Enzyme System
  • Cytochrome P 450 Enzymes
  • Cytochrome P 450 Families
  • Cytochrome P 450 Superfamily
  • Enzyme, Cytochrome P-450
  • Enzyme, P-450
  • Enzyme, P450
  • Enzymes, Cytochrome P-450
  • Enzymes, P-450
  • Enzymes, P450
  • P 450 Enzyme
  • P 450 Enzymes
  • P-450 Enzyme, Cytochrome
  • P-450 Enzymes, Cytochrome
  • Superfamily, CYP450
  • Superfamily, Cytochrome P-450
  • Superfamily, Cytochrome P450
  • Cytochrome P-450 Monooxygenase
  • Cytochrome P-450 Oxygenase
  • Cytochrome P-450-Dependent Monooxygenase
  • Cytochrome P 450 Dependent Monooxygenase
  • Cytochrome P 450 Monooxygenase
  • Cytochrome P 450 Oxygenase
  • Monooxygenase, Cytochrome P-450
  • Monooxygenase, Cytochrome P-450-Dependent

MeSH Record

Aspects Covered

28 allowable subheadings

Indexed with the subheadings administration & dosage, adverse effects, analysis, biosynthesis, blood, cerebrospinal fluid, chemical synthesis, chemistry, classification, deficiency, drug effects, economics, genetics, history, immunology, isolation & purification, metabolism, pharmacokinetics, pharmacology, physiology, poisoning, radiation effects, standards, supply & distribution, therapeutic use, toxicity, ultrastructure, urine.

MeSH Record

Indexing Annotation

general or unspecified; prefer specific cytochrome P-450's

MeSH Record

History Note

73; CYTOCHROME P-450 OXYGENASE was NM 1977-96

MeSH Record

Previous Indexing

  • Cytochromes (1966-1972)

MeSH Hierarchy

Tree Numbers

AMA Style

References

  1. National Library of Medicine. Cytochrome P-450 Enzyme System. Medical Subject Headings (MeSH). 2026. Unique ID D003577. http://id.nlm.nih.gov/mesh/2026/D003577
  2. Cytochrome P-450 Enzyme System. In: Wikipedia. https://en.wikipedia.org/wiki/Cytochrome_P450
  3. Cytochrome P-450 Enzyme System. In: Wikidata. https://www.wikidata.org/wiki/Q407693