Fig. 1.

Schematic representation of human respiratory mucins and their carbohydrate side chains. Mucins consist out of up to 5 subunits attached to each other by disulfide bonds. These subunits are highly glycosylated proteins with non-glycosylated ends. The depicted carbohydrate chain is only illustrative. Ala, Gly, Pro, Thr, Ga, GaN, Gn, and NA correspond respectively to alanine, glycine, proline, threonine, galactose, N-acetylgalactosamine, N-acetylglucosamine, and N-acetylneuraminic acid (adapted from Ref. [120]).