Oligosaccharides mucin structure

Figure 14.2 Representative oligosaccharide structures found on mammalian glycoproteins and glycolipids. The complex oligosaccharides may be bi-, tri-, or tetra-antennary the branches may be more or less elongated with 1—>4 linked lactosamine units, and they may or may not be sialylated. The SLex, Lea, and Leb structures represent the different blood group determinants often present on lipids, and the elongated core 2 structure is a mucin-type glycosylation. Proteoglycans have a common core to which a variety of linear acidic polysaccharides are attached.

A recent study by Beyer et al. (1979) has greatly illuminated the factors influencing structure in mucin oligosaccharides and it is discussed in detail below. 

Based on the structure of hog submaxillary mucin oligosaccharide side chains proposed by Baig and Aminoff (1972), another sialyltransfer-ase, responsible for the addition of sialic acid linked to j8-galactosyl residues, remains to be isolated from hog submaxillary tissues (see Figure 11). 

Figure 47-2. Structures of two 0-linked oligosaccharides found in (A) submaxillary mucins and (B) fe-tuin and in the sialoglycoprotein of the membrane of human red blood cells. (Modified and reproduced, with permission, from LennarzWJ The Biochemistry of Glycoproteins and Proteoglycans. Plenum Press, 1980.)...

D. Carlson, Structures and immunological properties of oligosaccharides isolated from pig submaxillary mucins, J. Biol. Chem., 243 (1968) 616-626. 

Pig submaxillary mucin (74) exists in two forms in individual glands one of these possesses A activity, and the other does not. Their gross compositions were identical. Five oligosaccharides were isolated, the largest having the structure... 

Ten sialic-acid-containing oligosaccharides and four neutral oligosaccharides have been purified from the major glycoprotein fraction of hog, submaxillary-gland mucin. H-N.m.r. spectroscopy at 360 MHz, in combination with methylation analysis and mass spectrometry, allowed the determination of their structures, which are partial structures of a pentasaccharide (see Fig. 42) having blood-group A activity.221... 

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