Recombinant human P450 forms 1A1, 1A2, and 1B1 catalyze the bioactivation of heterocyclic amine mutagens in Escherichia coli lacZ strains

Environ Mol Mutagen. 2001;38(1):12-8. doi: 10.1002/em.1045.


Three recombinant human P450 enzymes, forms 1A1, 1A2, and 1B1, were coexpressed with NADPH-cytochrome P450 reductase in an E. coli lacZ strain suitable for detection of the mutagenicity of heterocyclic and aromatic amines. The resulting strains expressed the recombinant P450 holoenzymes at high levels. MeIQ (2-amino-3,4-dimethylimidazo[4,5-f]quinoline) was activated effectively by P450 1A2, weakly by P450 1A1, and not detectably by P450 1B1. MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline) and Trp-P-2 (3-amino-1-methyl-5H-pyrido[4,3-b]indole) were activated by all three enzymes, with form 1A2 the most effective. These strains facilitate analysis of the substrate specificity of human P450 forms that participate in the metabolic activation of carcinogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aryl Hydrocarbon Hydroxylases*
  • Biotransformation
  • COS Cells
  • Carbolines / pharmacokinetics*
  • Catalysis
  • Cell Transformation, Neoplastic
  • Cytochrome P-450 CYP1A1 / metabolism*
  • Cytochrome P-450 CYP1A2 / metabolism*
  • Cytochrome P-450 CYP1B1
  • Cytochrome P-450 Enzyme System / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Lac Operon*
  • Quinolines / pharmacokinetics*
  • Quinoxalines / pharmacokinetics*
  • Substrate Specificity


  • Carbolines
  • Quinolines
  • Quinoxalines
  • 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline
  • 3-amino-1-methyl-5H-pyrido(4,3-b)indole
  • Cytochrome P-450 Enzyme System
  • Aryl Hydrocarbon Hydroxylases
  • CYP1B1 protein, human
  • Cytochrome P-450 CYP1A1
  • Cytochrome P-450 CYP1A2
  • Cytochrome P-450 CYP1B1
  • 2-amino-3,4-dimethylimidazo(4,5-f)quinoline