Novel core, backbone and peripheral region sequences of the oligosaccharides of foetal gastrointestinal mucins present in human meconium

Abstract

Structural and conformational studies have been carried out of the oligosaccharide chains of foetal gastrointestinal mucins purified from human meconium. Combined GC, MS and 1H NMR analysis has been used to characterise the twenty-six major mono- to hexasaccharides. These show seven different core regions (including unsubstituted GalNAc-ol). Extended glycosylation occurs on both branches at C6 and C3 of GalNAc-ol and both repeating type 1, Gal beta 1-3GlcNAc, and alternating type 1/type 2, Gal beta 1-3GlcNAc/Gal beta 1-4GlcNAc, sequences are found. Backbone type 1 sequences are linked via a GlcNAc beta 1-3Gal bond whereas Type 2 sequences can be linked additionally via a GlcNAc beta 1-6Gal bond either in a straight chain or as a branch, GlcNAc beta 1-3[GlcNAc beta 1-6]Gal. Peripheral substituents include Fuc alpha 1-2 and GlcNAc alpha 1-4 linked to Gal.