Drug metabolism by Escherichia coli expressing human cytochromes P450

Nat Biotechnol. 1997 Aug;15(8):784-8. doi: 10.1038/nbt0897-784.


The broad substrate specificity of the cytochrome P450 (P450) enzyme superfamily of heme-thiolate proteins lends itself to diverse environmental and pharmaceutical applications. Until recently, the primary drawback in using living bacteria to catalyze mammalian P450-mediated reactions has been the paucity of electron transport from NADPH to P450 via endogenous flavoproteins. We report the functional expression in Escherichia coli of bicistronic constructs consisting of a human microsomal P450 enzyme encoded by the first cistron and the auxiliary protein NADPH-P450 reductase by the second. Expression levels of P450s ranged from 35 nmol per liter culture to 350 nmol per liter culture, with expression of NADPH-P450 reductase typically ranging from 50% to 100% of that of P450. Transformed bacteria metabolized a number of typical P450 substrates at levels comparable to isolated bacterial membranes fortified with an NADPH-generating system. These rates compare favorably with those obtained using human liver microsomes as well as those of reconstituted in vitro systems composed of purified proteins, lipids, and cofactors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Catalysis
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P-450 Enzyme System / metabolism
  • DNA, Complementary / metabolism
  • Escherichia coli
  • Humans
  • NADH, NADPH Oxidoreductases / genetics
  • NADH, NADPH Oxidoreductases / metabolism
  • NADPH-Ferrihemoprotein Reductase
  • Operon
  • Pharmaceutical Preparations / metabolism*
  • Recombinant Proteins / biosynthesis
  • Substrate Specificity


  • DNA, Complementary
  • Pharmaceutical Preparations
  • Recombinant Proteins
  • Cytochrome P-450 Enzyme System
  • NADH, NADPH Oxidoreductases
  • NADPH-Ferrihemoprotein Reductase