Convenient Structural Analysis of Glycosphingolipids Using MALDI-QIT-TOF Mass Spectrometry with Increased Laser Power and Cooling Gas Flow

ArticleinJournal of Biochemistry 139(4):771-7 · May 2006with17 Reads
DOI: 10.1093/jb/mvj090 · Source: PubMed
Matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS) was applied to the structural characterization of neutral glycosphingolipids. Lithium adduct ions of glycosphingolipids were analyzed using MALDI-QIT-TOF MS under strong conditions of increased laser power and cooling gas flow. The relative intensities of fragment ions were increased under the strong conditions, and the resulting spectra revealed the presence of oligosaccharide ions fragmented from the glycosphingolipids. Consequently, the oligosaccharide sequences of the glycosphingolipids were readily obtained. To obtain more detailed structural information, MS/MS (MS2) and MS/MS/MS (MS3) analyses were performed with selection of the lactosylceramide and ceramide ions, respectively. The resulting data were sufficient to determine the structures of both the oligosaccharide and the ceramide moiety of each glycosphingolipid. The fragmentation patterns of MS2 and MS3 for Forssman glycolipid under the strong conditions were comparable to those of MS3 and MS4 obtained under standard conditions, respectively. Thus, MALDI-QIT-TOF MS with increased laser power and cooling gas flow is a convenient method for glycosphingolipid analysis.
    • "The fragmentation yields for oligosaccharides or glycolipids were found to be related to alkali metal ion size and electrostatic charge density. Li adducts increase fragmentations of labile glycosidic bonds as well as ceramide moieties of glycolipids [5,8,10,21]. Cs adducts decrease fragmentations of glycolipids, therefore molecular ions can be detected in the MS spectra [11,18]. "
    Article · Jan 2015 · Biochimica et Biophysica Acta
    • "This infusion-based lipidomic technique allows quantification of a high number of lipid species in small probes from intestine and liver. The approach is hampered by the fact that the method does not distinguish isomeric and isobaric lipid species [13][14][15]. Concerning sphingolipids, LC-MS-or LC-/MS/MS, shotgun-lipidomics, and MALDI imaging mass spectrometers are established as basic technical approaches. Using LC-MS/MS identification, quantification, and structural analysis of free sphingoid bases/phosphates, ceramides, monohexosylceramides, lactosylceramides, sphingomyelins and other glycosphingolipids are possible [16][17][18][19] . "
    [Show abstract] [Hide abstract] ABSTRACT: Identification and quantification of lipids, in particular sphingolipids from intestine and liver, using multidimensional mass spectrometry has dramatically improved our understanding of lipid-based molecular pathways and signaling. The editorial gives a short overview about basic technical approaches to characterize lipids from intestine and liver.
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    • "Matrix assisted laser desorption ionization has been successfully used to ionize multiple classes of SL such as Cer, HexCer, LacCer, ST, globosides, gangliosides, and SM505152. Sample preparation for MALDI analysis usually occurs by mixing a solution of small organic acid (matrix) with a solution containing the analyte of interest. A small volume, typically on the order of 0.5-1 μL, of this mixture is then spotted on a metal target plate and allowed to dry. "
    [Show abstract] [Hide abstract] ABSTRACT: Sphingolipids are a highly diverse category of molecules that serve not only as components of biological structures but also as regulators of numerous cell functions. Because so many of the structural features of sphingolipids give rise to their biological activity, there is a need for comprehensive or "sphingolipidomic" methods for identification and quantitation of as many individual subspecies as possible. This review defines sphingolipids as a class, briefly discusses classical methods for their analysis, and focuses primarily on liquid chromatography tandem mass spectrometry (LC-MS/MS) and tissue imaging mass spectrometry (TIMS). Recently, a set of evolving and expanding methods have been developed and rigorously validated for the extraction, identification, separation, and quantitation of sphingolipids by LC-MS/MS. Quantitation of these biomolecules is made possible via the use of an internal standard cocktail. The compounds that can be readily analyzed are free long-chain (sphingoid) bases, sphingoid base 1-phosphates, and more complex species such as ceramides, ceramide 1-phosphates, sphingomyelins, mono- and di-hexosylceramides, sulfatides, and novel compounds such as the 1-deoxy- and 1-(deoxymethyl)-sphingoid bases and their N-acyl-derivatives. These methods can be altered slightly to separate and quantitate isomeric species such as glucosyl/galactosylceramide. Because these techniques require the extraction of sphingolipids from their native environment, any information regarding their localization in histological slices is lost. Therefore, this review also describes methods for TIMS. This technique has been shown to be a powerful tool to determine the localization of individual molecular species of sphingolipids directly from tissue slices.
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