Covalent binding to apoprotein is a major fate of heme in a variety of reactions in which cytochrome P-450 is destroyed

Biochem Biophys Res Commun. 1986 Jul 16;138(1):193-8. doi: 10.1016/0006-291x(86)90265-2.


The heme in rat liver microsomal cytochrome P-450 was labeled with 14C or 3H and the microsomes were fractionated after in vitro incubations with a variety of agents known to destroy cytochrome P-450 heme. A major fraction of the heme label was irreversibly bound to apoprotein in all cases, including incubations with fluroxene, 1-octene, vinyl bromide, trichloroethylene, vinyl chloride, parathion, cumene hydroperoxide, NaN3, or iron-ADP complex. Label was also extensively bound to apoprotein when purified and reconstituted cytochrome P-450 was incubated with NADPH and vinyl chloride. This process appears to be widespread and involved to a significant extent in the cytochrome P-450 heme destruction observed with many compounds.

Publication types

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

MeSH terms

  • Alkenes / pharmacology
  • Animals
  • Azides / pharmacology
  • Benzene Derivatives / pharmacology
  • Cytochrome P-450 Enzyme System / metabolism*
  • Ethers / pharmacology
  • Heme / metabolism*
  • Microsomes, Liver / enzymology
  • Parathion / pharmacology
  • Rats
  • Sodium Azide
  • Trichloroethylene / pharmacology
  • Vinyl Chloride / pharmacology
  • Vinyl Compounds / pharmacology


  • Alkenes
  • Azides
  • Benzene Derivatives
  • Ethers
  • Vinyl Compounds
  • Trichloroethylene
  • Heme
  • Parathion
  • vinyl bromide
  • Cytochrome P-450 Enzyme System
  • Sodium Azide
  • 1-octene
  • cumene hydroperoxide
  • Vinyl Chloride