E Nudelman

1H-n.m.r. analysis of glycolipids possessing mono- and multi-meric X and Y haptens: characterization of two novel extended Y structures from human adenocarcinoma.

Analysis of glycolipids having repeating core-structures of type 2 chains ([Gal beta 1----4GlcNAc beta 1----3]nGal beta 1----4Glc beta 1----1Cer) by 1- and 2-dimensional high resolution 1H-n.m.r. spectroscopy shows that fucosylation alpha 1----3 to GlcNAc with or without fucosylation alpha 1----2 to Gal produces predictable chemical shifts of anomeric protons and systematic, glycosylation-induced shift changes. These effects were analyzed for a series of glycolipids of known structure bearing mono- and multimeric X [Gal beta 1----4(Fuc alpha 1----3)GlcNAc beta 1----3] and Y [Fuc alpha 1----2Gal beta 1----4-(Fuc alpha 1----3)GlcNAc beta 1----3] determinants, and were subsequently used to elucidate the primary saccharide structure of two novel glycolipids isolated from human liver adenocarcinoma. They are proposed to be Y determinants carried on a norhexaosylceramide core, with the following structures: (Formula: see text).

Monoclonal antibody directed to the stage-specific embryonic antigen (SSEA-1) reacts with a branched glycosphingolipid similar in structure to Ii antigen

Abstract A monoclonal antibody reacting with early mouse embryos and murine embryonal carcinoma cells (F9) defines the stage-specific embryonic antigen (SSEA-1). We now report that the antigen (SSEA-1) is a complex glycolipid with the branched lacto-N-glycosyl series. Antibody to SSEA-1 reacts strongly with the branched H 4 -glycosphingolipid but not with other various glycolipids so far tested. This reactivity was abolished by endo-β-galactosidase treatment. The homogeneous H 4 -glycolipid not only reacted with the monoclonal antibody to SSEA-1 but also with antibody to I-(Ma), i-(Dench) and with anti-H specific lectin. Chemical analysis, including methylation, also indicates that the glycolipid antigen had a close resemblance to I-antigen.

1H-n.m.r. analysis of type-2 chain lacto-gangliosides. Confirmation of structure of a novel cancer-associated fucoganglioside, α-NeuAc-(2→6)-β-d-Galp-(1→4)-β-d- GlcpNAc-(1→3)-β-d-Galp-(1→4)-[α-l-Fucp-(1→3)]-β-d-GlcpNAc-(1→3)-β-d-Galp-(1→4)-β-d- Glcp-(1→1)-Cer (VI6NeuAcIII3FucnLc6Cer)

Abstract Neolacto -glycosphingolipids, substituted with α-NeuAc-(2→3)- and -(2→6)-linked d -Gal p residues were analyzed by one- and two-dimensional 1 H-n.m.r. spectroscopy at 500 MHz in 49:1 (v/v) di( 2 H 3 )methyl sulfoxide-deuterium oxide solution. For the simplest structures analyzed, nLc 4 Cer, IV 3 NeuAcnLc 4 Cer, and IV 6 NeuAcnLc 4 Cer, sialosylation-induced changes in shifts of terminal and subterminal core residues were interpretable in terms of existing conformational models. Chemical shifts for H-3 e and H-3 a of NeuAc characteristic for the type of linkage, were also determined. In addition, regularly reproducible shifts were seen for H-1 and other resonances of terminal and subterminal core residues of all structures tested. Chemical-shift correlations proved to be useful in elucidating the structure of a unique ganglioside bearing an internal β- d -Gal p -(1→4)-[α- l -Fuc p -(1→3)]-β- d -Glc p NAc-(1→3) residue (“X-trisaccharide”) with an α-NeuAc-(2→6)-substituted terminal group.