Detailed Structural Characterization of Sphingolipids via 193 nm Ultraviolet Photodissociation and Ultra High Resolution Tandem Mass Spectrometry.

摘要: Sphingolipids serve not only as components of cellular membranes but also bioactive mediators numerous functions. As the biological activities these lipids are dependent on their structures, and due to limitations conventional ion activation methods employed during tandem mass spectrometry (MS/MS), there is a recognized need for development improved structure-specific comprehensive identification characterization. Here, positive-ionization mode 193 nm ultraviolet photodissociation (UVPD)-MS/MS has been implemented detailed structural characterization lipid species from range sphingolipid classes introduced spectrometer via electrospray ionization lithiated or protonated adducts. These include sphingosine d18:1(4E), dihydrosphingosine (sphinganine) d18:0, sphingadiene d18:2(4E,11Z), isomeric sphingolipids ceramide d18:1(4E)/18:0 dihydroceramide d18:0/18:1(9Z), ceramide-1-phosphate d18:1(4Z)/16:0, sphingomyelin d18:1(4E)/18:1(9Z) glycosphingolipids galactosyl d18:1(4E)/24:1(15Z) lactosyl d18:1(4E)/24:0, several endogenous present within porcine brain total extract. In addition product ions formed by higher energy collision dissociation (HCD), UVPD shown yield series novel structurally diagnostic resulting cleavage both carbon-carbon acyl chain double bonds direct localization site(s) unsaturation, well cleavages backbone N-C amide bond linkages. With timescales efficiencies similar those found in MS/MS strategies, this approach therefore promising new tool arsenal techniques toward providing complete elucidation automated, high-throughput analysis workflows. Graphical Abstract ᅟ.