Fundamental Sessions
Day 3, June 12（Fri.） 10:27-10:45 Room D (5F 511+512)
- 3D-O1-1027（1P-10）
Phospholipid sn-position analysis for elucidating biosynthetic pathways of photoreceptor-specific lipid metabolites
(1Tokyo Univ. Agr. Tech., 2Kyoto Univ.)
oReo Hayashida1, Bujinlkham Buyantogtokh1, Hiroshi Tsugawa1,2
Rod photoreceptor cells in the retina possess unique membrane structures enriched with lipids containing very long-chain polyunsaturated fatty acids (VLC-PUFAs). VLC-PUFA–containing phosphatidylcholines (PCs) have been implicated in visual dysfunction and aging-related diseases. However, their low abundance in ocular tissues has limited structural and metabolic analyses, and the metabolic pathways responsible for VLC-PUFA incorporation remain unclear. Identification of fatty-acid sn-positions is therefore important for understanding lipid biosynthesis and acyl-chain remodeling. In this study, an LC–MS/MS method utilizing bicarbonate adducts was applied to analyze sn-position isomers of VLC-PUFA PCs. Addition of ammonium bicarbonate to the mobile phase enabled detection of diagnostic ions from sn-1 fatty acids of PCs. Analysis of PC standard isomers showed concentration-dependent responses of diagnostic ions. Application to mouse eye extracts suggested that VLC-PUFAs are predominantly localized at the sn-1 position of PCs, with minor sn-2 incorporation.