Mucin Domains to Explore Disulfide-Dependent Dimer Formation

The viscoelastic properties needed for the protective functions of secretory mucins are in part conditional on the capacity of mucin macromolecules to form linear polymers stabilized by disulfide bonds. The individual mucin monomers have a distinctive structure, consisting of a long central peptide region of tandem repeat sequences, flanked by cysteine-rich regions at each end, which are presumed to mediate polymerization. Secretory mucins contain approx 60–80% carbohydrate, with extensive O-glycosylation in the central tandem repeat regions, and N-linked oligosaccharides in the peripheral regions (1).