Work

Structural diversity and specific distribution of O-glycans in normal human mucins along the intestinal tract

Year: 2004

Type: article

Abstract: Purified human mucins from different parts of the intestinal tract (ileum, cecum, transverse and sigmoid colon and rectum) were isolated from two individuals with blood group ALe(b) (A-Lewis(b)). After alkaline borohydride treatment the released oligosaccharides were structurally characterized by nano-ESI Q-TOF MS/MS (electrospray ionization quadrupole time-of-flight tandem MS) without prior fractionation or derivatization. More than 100 different oligosaccharides, with up to ten monosaccharide residues, were identified using this technique. Oligosaccharides based on core 3 structures, GlcNAc(beta1-3)GalNAc (where GlcNAc is N-acetyl-D-glucosamine and GalNAc is N-acetylgalactosamine), were widely distributed in human intestinal mucins. Core 5 structures, GalNAc(alpha1-3)GalNAc, were also recovered in all fractions. Moreover, a comparison of the oligosaccharide repertoire, with respect to size, diversity and expression of glycans and terminal epitopes, showed a high level of mucin-specific glycosylation: highly fucosylated glycans, found specifically in the small intestine, were mainly based on core 4 structures, GlcNAc-(beta1-3)[GlcNAc(beta1-6)]GalNAc, whereas the sulpho-Le(X) determinant carrying core 2 glycans, Gal(beta1-3)[GlcNAc(beta1-6)]-GalNAc (where Gal is galactose), was recovered mainly in the distal colon. Blood group H and A antigenic determinants were present exclusively in the ileum and cecum, whereas blood group Sd(a)/Cad related epitopes, GalNAc(beta1-4)[NeuAc(alpha2-3)]Gal (where NeuAc is N-acetylneuraminate), were found to increase along the length of the colon. Our findings suggest that mucins create an enormous repertoire of potential binding sites for micro-organisms that could explain the regio-specific colonization of bacteria in the human intestinal tract.

Source: Biochemical Journal

DOI: 10.1042/bj20040605

Authors: Catherine ROBBE, Calliope CAPON, Bernadette CODDEVILLE, Jean-Claude MICHALSKI

Institutions: Centre National de la Recherche Scientifique, Unité de Glycobiologie Structurale et Fonctionnelle, Université Lille 1, Université de Lille

Language: English

Topic: Glycosylation and Glycoproteins Research

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: bronze

Funders: Centre National de la Recherche Scientifique, Université Lille 1 - Sciences et Technologies