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Functional characterization of 20 allelic variants of CYP1A2

Miyabi Ito1, Yuki Katono1, Akifumi Oda2

  • 1Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.

Drug Metabolism and Pharmacokinetics
|May 30, 2015
PubMed

Insights

Genetic variations in cytochrome P450 1A2 (CYP1A2) affect drug metabolism. This study characterized 20 CYP1A2 variants, finding some inactive, some with reduced activity, and others with increased activity compared to wild-type, impacting drug efficacy.

Area of Science:

  • Pharmacogenomics
  • Enzymology
  • Molecular biology

Background:

  • Genetic variations in cytochrome P450 1A2 (CYP1A2) contribute to significant interindividual differences in drug metabolism and treatment outcomes.
  • Understanding the functional impact of these genetic variants is crucial for personalized medicine.

Purpose of the Study:

  • To functionally characterize 20 CYP1A2 allelic variants with amino acid substitutions.
  • To assess the impact of these variants on the enzymatic activity of CYP1A2 using specific substrates.

Main Methods:

  • Heterologous expression of recombinant CYP1A2 variant proteins in COS-7 cells.
  • Enzyme kinetic analyses using phenacetin and 7-ethoxyresorufin as representative CYP1A2 substrates.

Main Results:

  • Six variants (CYP1A2*4, *6, *8, *15, *16, *21) exhibited complete inactivity towards both substrates.
  • CYP1A2*11 displayed significantly reduced enzymatic activity with substrate-dependent changes in Km.
  • CYP1A2*14 and *20 showed increased activity compared to the wild-type CYP1A2*1 enzyme.

Conclusions:

  • This in vitro study provides a detailed functional profile of numerous CYP1A2 variants.
  • The characterized enzymatic activities of these variant proteins offer valuable insights for interpreting in vivo drug metabolism studies and clinical outcomes.
Keywords:
7-EthoxyresorufinCYP1A2Cytochrome P450Genetic polymorphismPhenacetin

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