Detection and Quantification of Conjunctival Mucins

Mucins are a family of high-molecular-weight glycoproteins secreted by the goblet and non-goblet epithelial cells of mucosal tissues. Molecular studies of human respiratory, intestinal, and mammary mucins have identified eight distinct mucins (MUC1-MUC8), which are expressed in distinct tissue-specific patterns.1 Mucins characteristically contain distinct serine- and threonine-rich tandem repeat domains that are heavily O-glycosylated. O-glycosylation of the repeat region of mucin apoproteins begins with the addition of N-acetylgalactosamine (GalNAc) to serine and threonine residues. Straight and branched sugar side chains are subsequently elaborated, resulting in extremely high-molecular-weight (>106 Da) glycoproteins containing 50–85% carbohydrate by weight.2