Lipopolysaccharide from Proteus mirabilis O29 induces changes in red blood cell membrane lipids and proteins.
Alterations in red blood cell (RBC) plasma membranes, i.e. in lipids and proteins, and osmotic fragility of these cells after treatment with Proteus mirabilis O29 endotoxin (lipolysaccharide (LPS)) were examined using a spin labelling method. At the highest concentration of LPS, insignificantly decreased fluidity of membrane lipids was observed. Changes in conformation of membrane proteins were determined by two covalently bound spin labels, 4-maleimido-2,2,6,6-tetramethylpiperidine-1-oxyl (MSL) and 4-iodoacetamido-2,2,6,6-tetramethylpiperidine-1-oxyl (ISL). The analysis of spectra of MSL and ISL showed modifications in membrane proteins in red blood cells treated with the highest concentration of lipopolysaccharide. On the other hand, in the case of isolated membranes, disturbances in membrane were observed for all concentrations of LPS. The alterations in membrane lipids and proteins are paralleled in a significant rise in osmotic fragility of RBCs upon endotoxin treatment. These results provide experimental evidence that P. mirabilis O29 LPS causes deleterious changes in membranes of human red blood cells. They show that action of lipopolysaccharide mainly concerns the membrane cytoskeleton.
Gwoździński
Krzysztof
K
Department of Molecular Biophysics, University of Łódź, Polish Academy of Sciences, 90-237 Łódź, Poland. kgwozdz@biol.uni.lodz.pl
Pieniazek
Anna
A
Kaca
Wiesław
W
D002462:Cell Membrane / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004578:Electron Spin Resonance Spectroscopy; D004731:Endotoxins / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D050356:Lipid Metabolism; D008070:Lipopolysaccharides / Q000378:metabolism*; D009995:Osmosis; D011513:Proteus mirabilis / Q000378:metabolism*; D013113:Spin Labels
D004731:Endotoxins; D008070:Lipopolysaccharides; D013113:Spin Labels