Evidence of regio-specific glycosylation in human intestinal mucins: presence of an acidic gradient along the intestinal tract.
Mucin glycans were isolated from different regions of the normal human intestine (ileum, cecum, transverse and sigmoid colon, and rectum) of two individuals with ALeb blood group. A systematic study of the monosaccharides and oligosaccharide alditols released by reductive beta-elimination from mucins was performed using gas chromatography, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, and nuclear magnetic resonance spectroscopy techniques. Important variations were observed in the mucin-associated oligosaccharide content with an increasing gradient of sialic acid from the ileum to the colon associated with a reverse gradient of fucose. Moreover, a comparative study of the Sda/Cad and ABH blood group determinants along the gastrointestinal tract showed the same reverse distribution in the two kinds of antigens. In addition, besides their heterogeneity, sialic acids presented considerable variations in the degree of O-acetylation in relation to glycan sialylation level. These data are discussed in view of recent concepts suggesting that the oligosaccharide composition of the gut constitutes a varied ecosystem for microorganisms that are susceptible to adapt there and possess the specific adhesion system and specific enzymes able to provide a carbohydrate nutrient.
Robbe
Catherine
C
Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche (UMR) CNRS/USTL 8576, IFR 118, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France.
Capon
Calliope
C
Maes
Emmanuel
E
Rousset
Monique
M
Zweibaum
Alain
A
Zanetta
Jean-Pierre
JP
Michalski
Jean-Claude
JC
D001789:Blood Group Antigens; D005643:Fucose / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006031:Glycosylation; D006801:Humans; D007422:Intestines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009005:Monosaccharides / Q000032:analysis; D009077:Mucins / Q000032:analysis* / Q000737:chemistry; D009844:Oligosaccharides / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis; D012794:Sialic Acids / Q000032:analysis; D013402:Sugar Alcohols / Q000032:analysis
D001789:Blood Group Antigens; D009005:Monosaccharides; D009077:Mucins; D009844:Oligosaccharides; D011134:Polysaccharides; D012794:Sialic Acids; D013402:Sugar Alcohols; D005643:Fucose