Immunochemistry of the Lewis-blood-group-system mass spectrometric analysis of permethylated Lea-, Leb-, and H-type 1 (LedH) blood-group active and related glycosphingolipids from human plasma
1981; Elsevier BV; Volume: 210; Issue: 1 Linguagem: Inglês
10.1016/0003-9861(81)90202-2
ISSN1096-0384
Autores Tópico(s)Carbohydrate Chemistry and Synthesis
ResumoGlycosphingolipids from human plasma with Lea, Leb, and H-type 1 (LedH) Lewis-blood-group activity have been analyzed after permethylation by electron impact mass spectrometry using an indirectly heated direct insertion probe. The spectra obtained are compared with that of permethylated neo-lactotetraosyl ceramide (Gl-3) from human plasma. The fragmentation patterns presented show clearly, that Lea and H-type 1 glycosphingolipids are ceramide pentasaccharides while Leb is a ceramide hexasaccharide. All Lewis-blood-group-active compounds investigated produced ions specific for type 1 carbohydrate chains. It is therefore concluded, that all compounds are derivatives of lacto-N-tetraose. The obtained spectra support the following sequences: Hexose-1→3-hexosamine[4←1-deoxyhexose]-hexose-hexose ceramide for the Lea derivatives; deoxyhexose-hexose-1→3-hexosamine4←1-deoxyhexose]-hexose-hexose ceramide for the Leb derivatives; and deoxyhexose-hexose-1→3-hexosamine-hexose-hexose ceramide for all H-type 1 (LedH) derivatives. In the case of the H-type 1 glycosphingolipids four subfractions were analyzed separately. While all four fractions contained the same carbohydrate sequence, significant differences were observed in the ceramide residues. Specific fragmentation patterns indicate the presence of sphingosine, icosasphingosine, and 4-hydroxysphinganine besides normal, unsaturated, and hydroxylated fatty acids in all Lewis-blood-group-active glycolipids.
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