Structures of sulfated oligosaccharides in human trachea mucin glycoproteins

Abstract

The structures of high molecular weight sulfated oligosaccharide chains in mucins purified from the sputum of a patient with cystic fibrosis and blood group H determinant were established. Reduced oligosaccharides released by treatment with alkaline borohydride were separated by ion exchange chromatography on DEAE-Agarose and a fraction containing multisulfated chains was further purified by lectin affinity chromatography to completely remove small amounts of sialylated chains. A major sulfated oligosaccharide fraction containing chains with an average of 160 to 200 sugar residues was isolated by gel filtration on BioGel P-10 columns and individual subfractions were characterized by methylation analysis, periodate oxidation and sequential glycosidase digestion before and after desulfation. Carbohydrate analysis yielded Fuc, Gal and GldNAc in a ratio of 1:2:2.1 and only one galactosaminitol residue for every 160- to 200 sugar residues. The average molecular weight of oligosaccharide chains in these fractions was between 27,000 and 40,000 daltons. Structural analysis showed that these high molecular weight chains contained varying amounts of the repeating unit shown in the following oligosaccharide. Only one in about every 10 repeating units contained sulfate esters. Several shorter chains which contain 2 to 3 sulfate esters were also isolated from this multisulfated oligosaccharide fraction. The structures proposed for these oligosaccharides indicate that they are lower molecular weight chains with the same general structure as those found in the high molecular weight sulfated oligosaccharides. Taken collectively, the results of these studies show that a major sulfated oligosaccharide fraction in respiratory mucin purified from the mucus of patients with cystic fibrosis contains high molecular weight branched chains that consist of a repeating oligosaccharide sequence with sulfate linked to the 6 positions of galactose and possibly GlcNAc residues in the side chains.

Mucins and their O-Glycans from human bronchial epithelial cell cultures

“…The acidic saccharides were considerably longer, as suggested from both the compositional analyses and the mass spectrometry studies (Table 4). Preliminary mass spectrometry analysis of these larger acidic oligosaccharides suggests that they are sulfated, rather than sialylated, a suggestion supported by observation of long sulfated oligosaccharides in human tracheal mucin glycoproteins (45). There were no apparent differences, however, in saccharide lengths or composition between the mucins analyzed from non-CF and CF HBE cultures.…”

Expression of mucin-associated tumor antigens is altered by cell density

“…Mild acid treatment consisted of 0.1 N H 2 SO 4 for 1 hr at 80°C (Spiro, 1966). Desulfation was accomplished with 0.06 M HCl in anhydrous methanol (Sangadala et al, 1993). After 4 hr at 32°C, samples were neutralized with 1 M NaOH.…”

Identification and characterization of sulfated glycoproteins from small cell lung carcinoma cells assisted by management of molecular charges

“…Many reports have shown that proteins containing sulfated glycans (i.e., sulfated glycoproteins) are associated with various diseases, such as cancer [1,2], cystic fibrosis [3,4], and osteoarthritis [5][6][7]. Most of these reports have indirectly demonstrated the presence of sulfated glycoproteins by experiments using sulfotransferase genes, specific antibodies for a particular sulfated glycans, and/or radioisotope [ 35 SO 4 ] labeling [8][9][10].…”