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Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction
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Lipopolysaccharide from Proteus mirabilis O29 induces changes in red blood cell membrane lipids and proteins

Krzysztof Gwoździński1, Anna Pieniazek, Wiesław Kaca

  • 1Department of Molecular Biophysics, University of Łódź, Polish Academy of Sciences, 90-237 Łódź, Poland. kgwozdz@biol.uni.lodz.pl

The International Journal of Biochemistry & Cell Biology
|January 18, 2003
PubMed

Insights

Proteus mirabilis O29 lipopolysaccharide (LPS) damages human red blood cell (RBC) membranes, altering lipids and proteins. This damage increases RBC osmotic fragility, indicating significant membrane disruption.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Microbiology

Background:

  • Red blood cell (RBC) membranes are crucial for cell integrity and function.
  • Endotoxins, such as lipopolysaccharide (LPS) from bacteria like Proteus mirabilis, can interact with and potentially damage host cells.
  • Understanding the specific effects of bacterial endotoxins on RBC membranes is important for comprehending host-pathogen interactions.

Purpose of the Study:

  • To investigate the impact of Proteus mirabilis O29 endotoxin (lipopolysaccharide, LPS) on the structure and function of human red blood cell (RBC) membranes.
  • To determine how LPS affects RBC membrane lipids, proteins, and osmotic fragility.
  • To elucidate the specific components of the RBC membrane targeted by LPS.

Main Methods:

  • Utilized a spin labeling method to examine alterations in RBC plasma membranes.
  • Employed spin labels 4-maleimido-2,2,6,6-tetramethylpiperidine-1-oxyl (MSL) and 4-iodoacetamido-2,2,6,6-tetramethylpiperidine-1-oxyl (ISL) to assess membrane protein conformation.
  • Analyzed changes in membrane lipid fluidity and protein structure in response to varying concentrations of LPS.
  • Measured the osmotic fragility of RBCs after LPS treatment.

Main Results:

  • Insignificant decrease in membrane lipid fluidity observed at the highest LPS concentration.
  • Significant modifications in membrane protein conformation detected in RBCs treated with high LPS concentrations.
  • Disturbances in isolated membranes observed across all tested LPS concentrations.
  • A significant increase in RBC osmotic fragility correlated with LPS treatment.
  • Evidence suggests LPS primarily affects the membrane cytoskeleton.

Conclusions:

  • Proteus mirabilis O29 LPS induces deleterious changes in human red blood cell membranes.
  • LPS alters both membrane lipids and proteins, leading to increased osmotic fragility.
  • The primary site of LPS action on RBCs appears to be the membrane cytoskeleton.

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