Binding of endotoxin to macrophages; interactions of spin-labelled saccharide residues

Simon K. Jackson*, Philip E. James, Christopher C. Rowlands, Bryn Mile

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

The molecular mechanisms of endotoxin action are poorly understood. A prerequisite to cellular activation by this agent must be interaction (binding) with the plasma membrane. In this study we have investigated the role of the polysaccharide region of endotoxin (LPS) in binding to macrophages and macrophage-like cell lines. The LPS molecules, from Escherichia coli O111.B4, J5 and the lipid-A, were spin labelled with 2,2,6,6-tetramethylpiperidine-N-oxyl (Tempo) free radical in their sugar residues, and examined by electron spin resonance spectroscopy. This is the first report of the synthesis of spin-labelled endotoxins. Measurement of the rotational correlation times (Tc) indicated that the saccharide residues do not bind to membrane surface structures and suggests that the binding of LPS to macrophages is mediated by the lipid acyl chains. Anti-sera to LPS from E. coli O111.B4 was effective in binding to the polysaccharide of the same LPS bound to the cell surface.

Original languageEnglish
Pages (from-to)165-170
Number of pages6
JournalBBA - Molecular Cell Research
Volume1135
Issue number2
DOIs
Publication statusPublished - 10 Jun 1992
Externally publishedYes

Keywords

  • Endotoxin
  • Macrophage
  • Saccharide
  • Spin label

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