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Hematin-Assisted Intramolecular Oxygen Transfer Mechanism Is Involved in the Formation of 8-Hydroxy-11,12-epoxyeicosa-5,9,14-trienoic Acid (8H-11, 12-EPETE) from 12-HPETE

  • C. R. Pace-Asciak
Part of the GWUMC Department of Biochemistry Annual Spring Symposia book series (GWUN)

Abstract

We recently described the isolation and structure of two hydroxyepoxides formed from 12-HPETE by an enzyme system present in rat lung (Pace-Asciak et al.,1983a). These were shown to be 8-hydroxy-ll,12-epoxy (8H-11,12-EPETE) and 10-hydroxy-ll,12-epoxy (1 OH-11,12-EPETE) eicosatrienoic acid. Evidence was presented to show that both oxygen atoms in the hydroxyepoxides were derived from molecular oxygen (Pace-Asciak et al., 1983a). Also, when [18O]oxygenated 12-HPETE was incubated with this enzyme preparation, 18O atoms were found in both the hydroxyl and the epoxide groups, suggesting that the hydroxyl group at carbon 8 and carbon 10 was derived from the hydroperoxide of 12-HPETE (Pace-Asciak et al., 1983a). However, whether the terminal hydroxyl group of the hydroperoxide of 12-HPETE was transferred via an inter- or intramolecular mechanism was not determined. The present chapter reports evidence with a mixture of [16O]- and [18O]-labeled 12-HPETE to show a unique intramolecular rearrangement of 12-HPETE into the hydroxyepoxides catalyzed by bovine hematin in a protein-free environment as well as by a rat lung cytosol fraction.

Keywords

Electron Paramagnetic Resonance Octadecadienoic Acid Ammonium Sulfate Fraction Eicosatrienoic Acid Epoxy Alcohol 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 1985

Authors and Affiliations

  • C. R. Pace-Asciak
    • 1
    • 2
  1. 1.The Hospital for Sick ChildrenTorontoCanada
  2. 2.Department of PharmacologyUniversity of TorontoTorontoCanada

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