Profiling glycosphingolipid structural detail: Periodate oxidation, electrospray, collision-induced dissociation and tandem mass spectrometry

✍ Scribed by Bruce B. Reinhold; Shui-Yung Chan; Steven Chan; Vernon N. Reinhold

• Book ID: 102965994
• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 869 KB
• Volume: 29
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210291206

✦ Synopsis

Abstract

Electrospray ionization mass spectrometry applied to methylated glycosphingolipid samples provides a sensitive molecular mass profile with no detectable fragmentation and little matrix background. In a bovine brain preparation, the components G~M1a~, G~D1a/b~ and G~T1a/b~ were characterized in detail and several minor entities, G~T1~, G~M3~, G~A1~, G~M2~, were mass profiled. Two additional materials, unrelated to the o‐, a‐, b‐ or c‐series, were characterized as hexosamine additions to G~M1~ and G~D1a~. Structural details of the major components within these samples were obtained by utilizing low‐energy collision tandem mass spectrometry and periodate oxidation, which could serve as a basis for more complex and higher molecular mass preparations. Fragment structures in the collision spectra were assigned with the assistance of C^1^H~3~ and C^2^H~3~ derivatization and by exploiting the natural carbohydrate and ceramide heterogeneity of the samples. Major fragments originate from C~1~O glycosidic rupture with few ring‐opening ions. Glycosidic fragments defined details that allow the determination of structural isomers, while specific fragments of the ceramide moiety differentiate sphingosine from N‐acyl heterogeneity. When contrasted with high‐energy (8 keV) tandem mass spectrometry, low‐energy collision‐induced dissociation of multiply charged molecular ions provided more abundant structurally diagnostic fragments.