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Lipopolysaccharide 3-deoxy-D-manno-octulosonic acid (Kdo) core determines bacterial association of secreted toxins.

Publication ,  Journal Article
Horstman, AL; Bauman, SJ; Kuehn, MJ
Published in: J Biol Chem
February 27, 2004

In contrast to cholera toxin (CT), which is secreted solubly by Vibrio cholerae across the outer membrane, heat-labile enterotoxin (LT) is retained on the surface of enterotoxigenic Escherichia coli (ETEC) via an interaction with lipopolysaccharide (LPS). We examined the nature of the association between LT and LPS. Soluble LT binds to the surface of LPS deep-rough biosynthesis mutants but not to lipid A, indicating that only the Kdo (3-deoxy-d-manno-octulosonic acid) core is required for binding. Although capable of binding truncated LPS and Kdo, LT has a higher affinity for longer, more complete LPS species. A putative LPS binding pocket is proposed based on the crystal structure of the toxin. The ability to bind LPS and remain associated with the bacterial surface is not unique to LT, as CT also binds to E. coli LPS. However, neither LT nor CT is capable of binding to the surface of Vibrio. The core structures of Vibrio and E. coli LPS differ in that Vibrio contains a phosphorylated single Kdo-lipid A, and E. coli LPS contains unphosphorylated Kdo2-lipid A. We determined that the phosphate group on the Kdo core of Vibrio LPS prevents CT from binding, resulting in the secretion of soluble toxin. Because LT binds E. coli LPS, it remains associated with the extracellular bacterial surface and is released in association with outer membrane vesicles. We propose that difference in the extracellular fates of LT and CT contribute to the differences in disease caused by ETEC and Vibrio cholerae.

Duke Scholars

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

February 27, 2004

Volume

279

Issue

9

Start / End Page

8070 / 8075

Location

United States

Related Subject Headings

  • Vibrio cholerae
  • Sugar Acids
  • Structure-Activity Relationship
  • Species Specificity
  • Phosphorylation
  • Molecular Structure
  • Molecular Conformation
  • Models, Molecular
  • Lipopolysaccharides
  • Escherichia coli Proteins
 

Citation

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Horstman, A. L., Bauman, S. J., & Kuehn, M. J. (2004). Lipopolysaccharide 3-deoxy-D-manno-octulosonic acid (Kdo) core determines bacterial association of secreted toxins. J Biol Chem, 279(9), 8070–8075. https://doi.org/10.1074/jbc.M308633200
Horstman, Amanda L., Susanne J. Bauman, and Meta J. Kuehn. “Lipopolysaccharide 3-deoxy-D-manno-octulosonic acid (Kdo) core determines bacterial association of secreted toxins.J Biol Chem 279, no. 9 (February 27, 2004): 8070–75. https://doi.org/10.1074/jbc.M308633200.
Horstman, Amanda L., et al. “Lipopolysaccharide 3-deoxy-D-manno-octulosonic acid (Kdo) core determines bacterial association of secreted toxins.J Biol Chem, vol. 279, no. 9, Feb. 2004, pp. 8070–75. Pubmed, doi:10.1074/jbc.M308633200.
Horstman AL, Bauman SJ, Kuehn MJ. Lipopolysaccharide 3-deoxy-D-manno-octulosonic acid (Kdo) core determines bacterial association of secreted toxins. J Biol Chem. 2004 Feb 27;279(9):8070–8075.

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

February 27, 2004

Volume

279

Issue

9

Start / End Page

8070 / 8075

Location

United States

Related Subject Headings

  • Vibrio cholerae
  • Sugar Acids
  • Structure-Activity Relationship
  • Species Specificity
  • Phosphorylation
  • Molecular Structure
  • Molecular Conformation
  • Models, Molecular
  • Lipopolysaccharides
  • Escherichia coli Proteins