Effect of lipids and proteins on the viscosity of gastric mucus glycoprotein

Biochem Biophys Res Commun. 1984 Jun 15;121(2):521-9. doi: 10.1016/0006-291x(84)90213-4.


The effect of associated lipids and covalently bound fatty acids, and the contribution of serum albumin and secretory IgA to the viscosity of dog gastric mucus glycoprotein was investigated. Using a cone/plate viscometer at shear rates between 1.15 - 230s -1, it was found that extraction of associated lipids from the glycoprotein lead to 80-85% decrease in the viscosity. Further loss (39%) in viscosity of the delipidated glycoprotein occurred following removal of covalently bound fatty acids. Reassociation of the delipidated glycoprotein with its neutral lipids increased the viscosity 3-fold, a 2.5-fold increase was obtained with glycolipids, and 2-fold with phospholipids. Preincubation of purified mucus glycoprotein with albumin or IgA resulted in the increase in viscosity. This increase in viscosity was proportional to albumin concentration up to 10%, and to IgA concentration up to 5%. The results show that interaction of lipids and proteins with mucus glycoprotein contributes significantly to the viscosity of gastric mucus.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chemical Phenomena
  • Chemistry
  • Dogs
  • Fatty Acids / metabolism
  • Gastric Mucosa / metabolism
  • Glycoproteins / metabolism*
  • Immunoglobulin A, Secretory / metabolism
  • Lipid Metabolism*
  • Mucus / metabolism*
  • Protein Binding
  • Proteins / metabolism*
  • Serum Albumin / metabolism
  • Viscosity


  • Fatty Acids
  • Glycoproteins
  • Immunoglobulin A, Secretory
  • Proteins
  • Serum Albumin