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A literature review of enzyme kinetic parameters for CYP3A4-mediated metabolic reactions of 113 drugs in human liver microsomes: structure-kinetics relationship assessment

Curr Drug Metab. 2006 Apr;7(3):231-49. doi: 10.2174/138920006776359329.

Abstract

Cytochrome P450 (CYP) enzymes represent a superfamily of hemoproteins that are involved in the metabolism of a wide variety of endogenous and exogenous compounds. For a given CYP enzyme, kinetic properties of a substrate are usually related to substrate lipophilicity (log P or log D(7.4)). In this review, enzyme kinetic parameters (K(m), V(max), and V(max)/K(m)) of 215 CYP3A4-mediated metabolic reactions of 113 drugs in human liver microsomes were obtained from the literature, and lipophilicity values of the 113 drugs were calculated using the ACD/Labs 8.0 program. A low degree of K(m)- or (V(max)/K(m))-lipophilicity correlation, but no V(max)-lipophilicity correlation, is exhibited for the CYP3A4-mediated reactions. Overall, K(m) decreases, but V(max)/K(m) increases, with increasing substrate lipophilicity, and V(max) appears to be independent of substrate lipophilicity. In other words, a low K(m) generally confers a high V(max)/K(m) ratio for a substrate. The degree of lipophilicity-kinetics correlations is related to both reaction types (or reaction mechanisms) and regiochemical positions (or physicochemical properties) of the reaction groups of the substrates. Among the categorized CYP3A4-mediated reactions, the best lipophilicity-kinetics correlation is achieved for carbon hydroxylation, followed by N-dealkylation. No or little lipophilicity-kinetics correlations are seen for N, S-oxidation and other reactions. Within the hydroxylation group, aliphatic hydroxylation shows the best lipophilicity-kinetics correlation while hydroxylation on a carbon atom adjacent to an aromatic ring does not show any lipophilicity-kinetics correlation. The detailed structural and kinetic data sets of the human liver microsomal CYP3A4-mediated reactions represent a specialized database useful for researchers working in the area of structure-metabolism relationship modeling and analysis.

Publication types

  • Review

MeSH terms

  • Animals
  • Biotransformation
  • Chemical Phenomena
  • Chemistry, Physical
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme System / metabolism*
  • Data Collection
  • Humans
  • Kinetics
  • Lipids / chemistry
  • Microsomes, Liver / enzymology*
  • Pharmaceutical Preparations / metabolism*
  • Structure-Activity Relationship
  • Substrate Specificity

Substances

  • Lipids
  • Pharmaceutical Preparations
  • Cytochrome P-450 Enzyme System
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human