Macroheterogeneities Induced by Disulfide Bond Reduction in Native Mucus

Area of Science:

• Biophysics
• Materials Science
• Biochemistry

Background:

• Disulfide bond reducing agents are used as mucolytics to treat mucus hypersecretions.
• Reducing disulfide bridges decreases mucus cross-linking, enhancing fluidity and altering micro- and mesoscale structures.
• The macroscopic reorganization of mucus upon disulfide bond reduction remains poorly understood.

Purpose of the Study:

• To investigate the macroscopic structural effects of tris(2-carboxyethyl)phosphine hydrochloride (TCEP) on native porcine gastric mucus.
• To correlate changes in macroscopic rheology with microscopic dynamics after TCEP treatment.
• To analyze the size of soluble macromolecules in TCEP-treated mucus.

Main Methods:

• Exposure of porcine gastric mucus to varying concentrations of TCEP.
• Measurement of macroscopic rheological properties.
• Analysis of microscopic dynamics and soluble macromolecule size.

Main Results:

• TCEP treatment led to increased macroscopic heterogeneity in mucus, suggesting phase separation.
• The size of suspendable macromolecules in the soluble mucus fraction remained constant despite increasing TCEP concentration.
• Disulfide bond reduction significantly altered mucus structure at the macroscopic level.

Conclusions:

• TCEP induces phase separation and macroscopic heterogeneity in gastric mucus.
• Macromolecule size is not significantly affected by TCEP-induced disulfide bond reduction.
• Understanding these structural changes is crucial for optimizing mucolytic therapies and improving mucus clearance mechanisms.