Self-association of mucin

Biomacromolecules. Fall 2000;1(3):325-34. doi: 10.1021/bm005532m.

Abstract

Aggregation phenomena in aqueous solutions of purified human tracheobronchial mucin have been studied by rheological methods, steady-state fluorescence, quasielastic light scattering, and spin probe techniques. At temperatures below 30 degrees C and concentrations above 15 mg/mL and in the absence of chaotropic agents, mucin solutions are viscoelastic gels. A gel-sol transition is observed at temperatures above 30 degrees C that is manifested by the diminishing storage modulus and a loss tangent above unity throughout the studied frequency range of the oscillatory shear. No decline in the mucin molecular weight is observed by size-exclusion chromatography above 30 degrees C in the absence of redox agents or proteolytic enzymes. Aggregation of hydrophobic protein segments of the mucin chains at 37 degrees C is indicated by QELS experiments. The decreasing polarity of the microenvironment of pyrene solubilized into mucin solutions at temperatures above 30 degrees C, concomitant with the gel-sol transition, shows the hydrophobicity of the formed aggregates. ESR spectra of the fatty acid spin probe, 16-doxylstearic acid indicate that the aggregate-aqueous interface becomes more developed at elevated temperatures.

MeSH terms

  • Bronchi / chemistry*
  • Buffers
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Electron Spin Resonance Spectroscopy
  • Electrophoresis, Polyacrylamide Gel
  • Humans
  • Indicators and Reagents
  • Light
  • Mucins / chemistry*
  • Mucins / isolation & purification
  • Rheology
  • Scattering, Radiation
  • Spectrometry, Fluorescence
  • Thermodynamics
  • Trachea / chemistry*

Substances

  • Buffers
  • Indicators and Reagents
  • Mucins