Application of electrospray mass spectrometry to the structural determination of glycosylphosphatidylinositol membrane anchors

Isabelle R. E. Nett, Angela Mehlert, Douglas Lamont, Michael A. J. Ferguson

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    6 Citations (Scopus)


    The addition of glycosylphosphatidylinositol (GPI) anchors to proteins is an important posttranslational modification in eukaryotic cells. The complete structural elucidation of GPI anchors is a complex process that requires relatively large amounts of starting material. In this paper, we assess the degree of structural information that can be obtained by applying electrospray mass spectrometry and tandem mass spectrometry to permethylated GPI glycans prepared from a well-characterized GPI-anchored glycoprotein, the variant surface glycoprotein from Trypanosoma brucei. All GPI glycans contain a non-N-acetylated glucosamine residue, and permethylation leads to the formation of a fixed positive charge on the glycans, in the form of a quaternary amine. The permethylated glycans were detected as [M +- Na](2+-) ions, and tandem mass spectrometry of these ions produced substantial, albeit incomplete, structural information on the branching patterns and linkage types for various GPI glycoforms of the variant surface glycoprotein.

    Original languageEnglish
    Pages (from-to)576-585
    Number of pages10
    Issue number5
    Publication statusPublished - May 2010


    • glycosylphosphatidylinositol
    • GPI anchor
    • mass spectrometry
    • Trypanosoma brucei
    • variant surface glycoprotein
    • MS

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