title: Comparative study of serine-plasmalogens in human retina and optic nerve: identification of atypical species with odd carbon chains.
abstract: The objective of this work was to detect and identify phosphatidylserine plasmalogen species in human ocular neurons represented by the retina and the optic nerve. Plasmalogens (vinyl-ether bearing phospholipids) are commonly found in the forms of phosphatidylcholine and phosphatidylethanolamine in numerous mammalian cell types, including the retina. Although their biological functions are unclear, the alteration of cellular plasmalogen content has been associated with several human disorders such as rhizomelic chondrodysplasia punctata Type 2 and primary open-angle glaucoma. By using liquid chromatography coupled to high-resolution and tandem mass spectrometry, we have identified for the first time several species of phosphatidylserine plasmalogens, including atypical forms having moieties with odd numbers of carbons and unsaturation in sn-2 position. Structural elucidation of the potential phosphatidylserine ether linked species was pursued by performing MS(3) experiments, and three fragments are proposed as marker ions to deduce which fatty acid is linked as ether or ester on the glycerol backbone. Interpretation of the fragmentation patterns based on this scheme enabled the assignment of structures to the m/z values, thereby identifying the phosphatidylserine plasmalogens.
authors.affiliation: Nestlé Research Center, Vers-chez-les-Blanc, Lausanne,  Switzerland.
authors.forename: Kornél
authors.initials: K
authors.lastname: Nagy
authors.forename: Viral Vishnuprasad
authors.initials: VV
authors.lastname: Brahmbhatt
authors.forename: Olivier
authors.initials: O
authors.lastname: Berdeaux
authors.forename: Lionel
authors.initials: L
authors.lastname: Bretillon
authors.forename: Frédéric
authors.initials: F
authors.lastname: Destaillats
authors.forename: Niyazi
authors.initials: N
authors.lastname: Acar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009900:Optic Nerve / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D010718:Phosphatidylserines / Q000737:chemistry*; D010955:Plasmalogens / Q000737:chemistry*; D012160:Retina / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D012694:Serine / Q000737:chemistry*; D013045:Species Specificity; D053719:Tandem Mass Spectrometry
chemical_list: D010718:Phosphatidylserines; D010955:Plasmalogens; D012694:Serine; D002244:Carbon