LC-MS/MS analysis of epoxyalcohols and epoxides of arachidonic acid and their oxygenation by recombinant CYP4F8 and CYP4F22
(English)Manuscript (preprint) (Refereed)
Cytochrome P450 4F22 (CYP4F22) and CYP4F8 are expressed in epidermis, and mutations of CYP4F22 are associated with lamellar ichthyosis. Epoxyalcohols (HEETs) and epoxides (EETs) derived from 20:4n-6 appear to be important for the water permeability barrier of normal skin. Our aim was to systematically study the MS/MS spectra and fragmentation of these compounds and to determine whether they were oxidized by CYP4F22 or CYP4F8 expressed in yeast. HEETs were prepared from 15-hydroperoxyeicosatetraenoic acid (15-HPETE), 12-HPETE, and their [2H8]labeled isotopomers, and separated by normal phase-HPLC with on-line MS/MS analysis. CYP4F22 oxygenated 20:4n-6 at C-18, whereas metabolites of HEETs could not be identified. CYP4F8 formed w3-hydroxy metabolites of HEETs derived from 12R-HPETE with 11,12-epoxy-10-hydroxy configuration, but not its 8-hydroxy isomer, or HEETs from 15S-HPETE. 8,9-EET and 11,12-EET were also subject to ω3 hydroxylation by CYP4F8, whereas 14,15-EET was not a substrate. We conclude that CYP4F8 and CYP4F22 oxidize 20:4n-6 and that CYP4F8 selectively oxidizes 8,9-EET, 11,12-EET, and 10,11R,12R-HEET at the ω3 position.
Epoxyeicosatrienoic acids, electrospray ionization, hepoxilins, ichthyosis
Pharmacology and Toxicology
Research subject Biochemical Pharmacology
IdentifiersURN: urn:nbn:se:uu:diva-109714OAI: oai:DiVA.org:uu-109714DiVA: diva2:273614