Skip to main content
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1987 Mar;84(5):1172–1176. doi: 10.1073/pnas.84.5.1172

Hydrocarbon formation in the reductive cleavage of hydroperoxides by cytochrome P-450.

A D Vaz, M J Coon
PMCID: PMC304388  PMID: 3103131

Abstract

Evidence is presented that cytochrome P-450 catalyzes the reductive cleavage of hydroperoxides. For example, in a reconstituted system containing rabbit liver microsomal P-450 form 2, NADPH-cytochrome P-450 reductase, and NADPH, cumyl hydroperoxide yields acetophenone and methane, but no cumyl alcohol is formed. The stoichiometry of the reaction and similar results with alpha-methylbenzyl, benzyl, and t-butyl hydroperoxides are in accord with the following general equation, in which X represents an alkyl group and R and R' are either alkyl groups or hydrogen atoms in the starting peroxide: XRR'C-OOH + NADPH + H+----XRCO + R'H + H2O + NADP+. Because 13-hydroperoxy-9,11-octadecadienoic acid yields pentane under these conditions, we propose that the known formation of alkanes and aldehydes in membrane lipid peroxidation involves reductive cleavage by P-450 to give the products predicted by the above equation. The cleavage reaction is thought to involve stepwise one-electron transfer, resulting in homolysis of the peroxide oxygen-oxygen bond and generation of an alkoxy radical, with beta-scission of the latter followed by reduction of the secondary radical to the hydrocarbon. In accordance with this scheme, when the cleavage reaction with cumyl hydroperoxide was done in 2H2O, deuteromethane was formed.

Full text

PDF
1172

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Aust S. D., Roerig D. L., Pederson T. C. Evidence for superoxide generation by NADPH-cytochrome c reductase of rat liver microsomes. Biochem Biophys Res Commun. 1972 Jun 9;47(5):1133–1137. doi: 10.1016/0006-291x(72)90952-7. [DOI] [PubMed] [Google Scholar]
  2. Blake R. C., 2nd, Coon M. J. On the mechanism of action of cytochrome P-450. Spectral intermediates in the reaction of P-450LM2 with peroxy compounds. J Biol Chem. 1980 May 10;255(9):4100–4111. [PubMed] [Google Scholar]
  3. Castro C. E., Wade R. S., Belser N. O. Biodehalogenation: reactions of cytochrome P-450 with polyhalomethanes. Biochemistry. 1985 Jan 1;24(1):204–210. doi: 10.1021/bi00322a029. [DOI] [PubMed] [Google Scholar]
  4. Coon M. J., van der Hoeven T. A., Dahl S. B., Haugen D. A. Two forms of liver microsomal cytochrome P-450, P-450lm2 and P-450LM4 (rabbit liver). Methods Enzymol. 1978;52:109–117. doi: 10.1016/s0076-6879(78)52012-0. [DOI] [PubMed] [Google Scholar]
  5. Ekström G., Ingelman-Sundberg M. Cytochrome P-450-dependent lipid peroxidation in reconstituted membrane vesicles. Biochem Pharmacol. 1984 Aug 1;33(15):2521–2523. doi: 10.1016/0006-2952(84)90729-9. [DOI] [PubMed] [Google Scholar]
  6. French J. S., Coon M. J. Properties of NADPH-cytochrome P-450 reductase purified from rabbit liver microsomes. Arch Biochem Biophys. 1979 Jul;195(2):565–577. doi: 10.1016/0003-9861(79)90383-7. [DOI] [PubMed] [Google Scholar]
  7. Gorsky L. D., Koop D. R., Coon M. J. On the stoichiometry of the oxidase and monooxygenase reactions catalyzed by liver microsomal cytochrome P-450. Products of oxygen reduction. J Biol Chem. 1984 Jun 10;259(11):6812–6817. [PubMed] [Google Scholar]
  8. HOCHSTEIN P., ERNSTER L. ADP-ACTIVATED LIPID PEROXIDATION COUPLED TO THE TPNH OXIDASE SYSTEM OF MICROSOMES. Biochem Biophys Res Commun. 1963 Aug 14;12:388–394. doi: 10.1016/0006-291x(63)90111-6. [DOI] [PubMed] [Google Scholar]
  9. Haugen D. A., Coon M. J. Properties of electrophoretically homogeneous phenobarbital-inducible and beta-naphthoflavone-inducible forms of liver microsomal cytochrome P-450. J Biol Chem. 1976 Dec 25;251(24):7929–7939. [PubMed] [Google Scholar]
  10. Hrycay E. G., O'Brien P. J. Cytochrome P-450 as a microsomal peroxidase utilizing a lipid peroxide substrate. Arch Biochem Biophys. 1971 Nov;147(1):14–27. doi: 10.1016/0003-9861(71)90304-3. [DOI] [PubMed] [Google Scholar]
  11. Kato R., Iwasaki K., Shiraga T., Noguchi N. Evidence for the involvement of cytochrome P-450 in reduction of benzo(a)pyrene 4,5-oxide by rat liver microsomes. Biochem Biophys Res Commun. 1976 Jun 7;70(3):681–687. doi: 10.1016/0006-291x(76)90646-x. [DOI] [PubMed] [Google Scholar]
  12. Lai C. S., Grover T. A., Piette L. H. Hydroxyl radical production in a purified NADPH--cytochrome c (P-450) reductase system. Arch Biochem Biophys. 1979 Apr 1;193(2):373–378. doi: 10.1016/0003-9861(79)90042-0. [DOI] [PubMed] [Google Scholar]
  13. Lindstrom T. D., Aust S. D. Studies on cytochrome P-450-dependent lipid hydroperoxide reduction. Arch Biochem Biophys. 1984 Aug 15;233(1):80–87. doi: 10.1016/0003-9861(84)90603-9. [DOI] [PubMed] [Google Scholar]
  14. Lu A. Y., West S. B. Multiplicity of mammalian microsomal cytochromes P-45. Pharmacol Rev. 1979 Dec;31(4):277–295. [PubMed] [Google Scholar]
  15. Nordblom G. D., Coon M. J. Hydrogen peroxide formation and stoichiometry of hydroxylation reactions catalyzed by highly purified liver microsomal cytochrome P-450. Arch Biochem Biophys. 1977 Apr 30;180(2):343–347. doi: 10.1016/0003-9861(77)90047-9. [DOI] [PubMed] [Google Scholar]
  16. Nordblom G. D., White R. E., Coon M. J. Studies on hydroperoxide-dependent substrate hydroxylation by purified liver microsomal cytochrome P-450. Arch Biochem Biophys. 1976 Aug;175(2):524–533. doi: 10.1016/0003-9861(76)90541-5. [DOI] [PubMed] [Google Scholar]
  17. Oprian D. D., Vatsis K. P., Coon M. J. Kinetics of reduction of cytochrome P-450LM4 in a reconstituted liver microsomal enzyme system. J Biol Chem. 1979 Sep 25;254(18):8895–8902. [PubMed] [Google Scholar]
  18. Poyer J. L., Floyd R. A., McCay P. B., Janzen E. G., Davis E. R. Spin-trapping of the trichloromethyl radical produced during enzymic NADPH oxidation in the presence of carbon tetrachloride or bromotrichloromethane. Biochim Biophys Acta. 1978 Mar 20;539(3):402–409. doi: 10.1016/0304-4165(78)90044-2. [DOI] [PubMed] [Google Scholar]
  19. Rahimtula A. D., O'Brien P. J. Hydroperoxide catalyzed liver microsomal aromatic hydroxylation reactions involving cytochrome P-450. Biochem Biophys Res Commun. 1974 Sep 9;60(1):440–447. doi: 10.1016/0006-291x(74)90223-x. [DOI] [PubMed] [Google Scholar]
  20. Sugiura M., Iwasaki K., Kato R. Reduction of tertiary amine N-oxides by liver microsomal cytochrome P-450. Mol Pharmacol. 1976 Mar;12(2):322–334. [PubMed] [Google Scholar]
  21. Svingen B. A., Buege J. A., O'Neal F. O., Aust S. D. The mechanism of NADPH-dependent lipid peroxidation. The propagation of lipid peroxidation. J Biol Chem. 1979 Jul 10;254(13):5892–5899. [PubMed] [Google Scholar]
  22. Uehleke H., Hellmer K. H., Tabarelli S. Binding of 14 C-carbon tetrachloride to microsomal proteins in vitro and formation of CHC1 3 by reduced liver microsomes. Xenobiotica. 1973 Jan;3(1):1–11. doi: 10.3109/00498257309151495. [DOI] [PubMed] [Google Scholar]
  23. Wendel A., Dumelin E. E. Hydrocarbon exhalation. Methods Enzymol. 1981;77:10–15. doi: 10.1016/s0076-6879(81)77004-6. [DOI] [PubMed] [Google Scholar]
  24. White R. E., Coon M. J. Oxygen activation by cytochrome P-450. Annu Rev Biochem. 1980;49:315–356. doi: 10.1146/annurev.bi.49.070180.001531. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES