Novel exogenous heme-dependent expression of mammalian cytochrome P450 using baculovirus

Arch Biochem Biophys. 1989 Nov 1;274(2):481-90. doi: 10.1016/0003-9861(89)90461-x.


Rat P450 IIA1 is a membrane-bound hemoprotein that catalyzes the 7 alpha- and 6 alpha-hydroxylation of testosterone. A recombinant baculovirus, containing the cDNA encoding IIA1, was constructed and used to infect Spodoptera frugiperda cells. Infected cells contained up to 10% IIA1 protein as quantified by Western blot analysis; however, only a small percentage of this protein contained heme and was catalytically active. Addition of hemin to the culture medium during the course of viral infection resulted in a marked sixfold increase in both testosterone hydroxylase activity and heme-containing IIA1 protein. When the exogenously added protoheme was substituted with modified heme molecules containing hydrogen or ethyl groups at the 2 and 4 positions of the protoporphyrin IX, enzymes with only marginal changes in catalytic properties were produced. These data indicate that baculovirus can be used as a system to produce high levels of mammalian cytochrome P450s containing custom modified heme moieties.

MeSH terms

  • Animals
  • Apoproteins / metabolism
  • Aryl Hydrocarbon Hydroxylases*
  • Cytochrome P-450 Enzyme System / biosynthesis
  • Cytochrome P-450 Enzyme System / metabolism*
  • Genetic Vectors
  • Heme / analogs & derivatives
  • Heme / pharmacology*
  • Hemin / pharmacology
  • Insect Viruses / genetics*
  • Rats
  • Recombination, Genetic
  • Spectrophotometry
  • Steroid Hydroxylases / metabolism


  • Apoproteins
  • Heme
  • Hemin
  • Cytochrome P-450 Enzyme System
  • Steroid Hydroxylases
  • Aryl Hydrocarbon Hydroxylases
  • testosterone 7-alpha-hydroxylase, hamster