Interaction of intestinal disaccharidases with phospholipids: Effect of cholesterol

Chinnaswamy Tiruppathi, David H. Alpers, Bellur Seetharam

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Although the rat intestinal brush border disaccharidases are the most easily solubilized protein com-ponents, the nature of the lipid-protein interactions in the membrane is incompletely understood. Phospholipid vesicles were prepared using the lecithin fraction from brush border membranes and synthetic lecithins. Addition of cholesterol to brush border lecithins enhanced the binding of disaccharidases, but not of alkaline phosphatase. The addition of cholesterol to synthetic lecithin vesicles enhanced the binding of disaccharidases only when added above the transition temperature of the lecithin used. The maximal effect occurred at an equimolar ratio of lecithin to cholesterol. Binding of disaccharidases to phospholipid vesicles was independent of charge or the nature of the polar head group, and the enzyme was inserted so that the catalytic domain was excluded from the lipid matrix. These results demonstrate that membrane attachment of disaccharidases is hydrophobic, involving primarily fatty acyl chains and an interaction with cholesterol. The membrane interaction does not seem to affect enzyme activity.

Original languageEnglish
Pages (from-to)965-970
Number of pages6
JournalJournal of pediatric gastroenterology and nutrition
Volume4
Issue number6
DOIs
StatePublished - Dec 1985

Keywords

  • Cholesterol
  • Disaccharidases
  • Membrane binding

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