Structural characterization of neutral oligosaccharides of human H⁺Le^b+ gastric mucin

The structure of carbohydrate chains of human gastric mucin was investigated. The mucin, purified from pronase-degraded gastric aspirates of the secretors with blood group H⁺Le^b, was subjected to alkaline borohydride treatment and a heterogeneous population of neutral (72.1%) and acidic (27.9%) oligosaccharide alditols was obtained. Ten oligosaccharides, representing 80.3% of the neutral oligosaccharide fraction, have been purified to homogeneity and their structures determined. These oligosaccharides ranged in length from 4 to 12 sugar units and contained mono-, bi-, and triantennary structures. Based on hemagglutination inhibition data in H-anti-H, Le^b-anti-Le^b, and I-anti-I systems, and the results of structural analyses, the authors present the structures for these oligosaccharides.