Disulfide bond and reactive oxygen species (ROS)

Disulfide bonds and reactive oxygen species (ROS) are critical chemical targets in the management of obstructive airway diseases and chronic infections. Disulfide bonds (S-S) are the primary covalent linkages between cysteine residues in mucin glycoproteins, such as MUC5AC and MUC5B, which determine the viscoelastic properties of mucus (PMID: 24841108). In bacterial biofilms, these bonds also contribute to the stability of the extracellular polymeric substance (EPS) matrix, protecting pathogens from the host immune system and antibiotics (PMID: 30108273). Reactive oxygen species, including superoxide and hydrogen peroxide, are elevated in inflamed airways and contribute to tissue damage and the oxidation of mucus components, further increasing viscosity (PMID: 11588360). Drugs like N-acetylcysteine (NAC) act as mucolytics by reducing these disulfide bonds to free sulfhydryl groups, thereby thinning the mucus and disrupting biofilm integrity (PubChem CID 12035). Additionally, NAC serves as a precursor to glutathione, the body's primary antioxidant, helping to neutralize ROS and mitigate oxidative stress in diseases like cystic fibrosis and COPD (StatPearls: N-Acetylcysteine).

Other names

S-S bondsMucin cross-linksExtracellular polymeric substances (EPS) bondsReactive oxygen speciesROSOxidative stress markers

Reduction of disulfide bonds to sulfhydryl groups to decrease viscosity and direct scavenging of reactive oxygen species.