Glycan Composition of Salivary Mucins

Mucin MG2 is less than a tenth the size of MG1, 355 amino acids mol wt 39 kDa. It consists of a single repeat domain with separate N- and C-terminal domains that are not VWF-related. The N-terminal domain has five cysteine residues, but the C-terminal domain has none and the secreted protein is probably a mixture of monomers and head-to-head disulfide dimers. 

MGl and MG2 account for the smooth surface of the oral mucosa and the viscosity of whole saliva. There are four monosaccharides associated with these mucins, of which three are illustrated in Fig. 12.5 W-acetyl galactosamine, L-fucose (6-deoxy-L-galactose), 

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