Mucin polymer disulfide bridge (null)

Mucin polymer disulfide bridges are covalent bonds formed between cysteine residues of mucin polypeptides, enabling the polymerization of secreted mucins such as MUC2, MUC5AC, and MUC5B into large, gel-forming networks that constitute mucus on respiratory, gastrointestinal, and other mucosal surfaces[1][2][3][4][5][6]. These disulfide bridges are crucial for producing the viscoelastic and barrier properties of mucus. The process occurs during mucin biosynthesis in the secretory pathway, is regulated by pH and calcium, and is responsible for cross-linking mucin monomers into functional polymers. Dysfunctional formation or abnormal reduction of these bridges alters mucus structure and is implicated in various diseases characterized by impaired or excessive mucus, such as cystic fibrosis, COPD, and certain intestinal disorders[2][4][5][6].

Other names

Disulfide bond in mucin polymerMucin intermolecular disulfide bridgeMucin N-terminal/C-terminal disulfide bonds

Reducing agents (e.g., N-acetylcysteine) may cleave disulfide bonds in mucin polymers, reducing mucus viscosity indirectly. Inhibitors of mucin secretion may reduce overall polymer formation.