57 varieties: the human cytochromes P450
Related Experiment Video
Updated: Aug 24, 2026

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
1School of Biomedical and Molecular Sciences, University of Surrey, UK. d.lewis@surrey.ac.uk
Abstract:
The human cytochrome P450 (CYP) complement of heme-thiolate enzymes is reviewed. Of the 57 individual P450s characterized in Homo sapiens thus far, it is apparent that approximately one-half are associated with the metabolism of drugs and other xenobiotics, whereas the other half have endogenous functions in steroid, prostanoid, eicosanoid and fatty acid metabolism. This review covers the extent of enzyme functionality for the known human P450s, focusing primarily on their role in the Phase I metabolism of foreign compounds, which involves the CYP1, CYP2 and CYP3 families.
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Electron Transport Chain: Complex III and IV
Five-Membered Heterocyclic Aromatic Compounds: Overview
Pharmacogenetics of Drug Metabolism: Overview
Principles of Pharmacogenetics: Types of Genetic Variants
Cofactors and Coenzymes
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...

