The origin of hydroxy-cyclohexenone fatty acids from skin barrier protein and relevance to covalent binding of ceramides.

ABSTRACT: Lipid constituents of the skin permeability barrier include a portion of ceramides and fatty acids covalently bound to the barrier protein. The covalent binding requires enzymatic oxidation of linoleate (C18:2) esterified to skin-specific acylceramides, forming a reactive 9,10-epoxy-11E-13-keto derivative. Barrier proteins treated with alkali release the bound lipids and as described recently, including two prominent cyclic linoleate derivatives, C18 hydroxy-cyclohexenone fatty acids. Herein we addressed the origin of these cyclic products by alkali treatment of potential precursors. A UV-based assay indicated the rates of Michael adduction of 9,10-epoxy-11E-13-keto to cysteine are two orders of magnitude faster than for a typical unsaturated keto fatty acid, and 10-fold faster for the dih

SUBMITTER: Noguchi S 

PROVIDER: S-EPMC12274931 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature