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Lipopolysaccharide‐binding protein mediates CD14‐independent intercalation of lipopolysaccharide into phospholipid membranes
Author(s) -
Schromm Andra B.,
Brandenburg Klaus,
Rietschel Ernst Th.,
Flad Hans-Dieter,
Carroll Stephen F.,
Seydel Ulrich
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(96)01338-5
Subject(s) - cd14 , lipopolysaccharide , chemistry , lipopolysaccharide binding protein , phospholipid , intercalation (chemistry) , microbiology and biotechnology , membrane , lipid a , cell membrane , biophysics , biochemistry , receptor , biology , immunology , inorganic chemistry
Lipopolysaccharides (LPS, endotoxin) stimulate mononuclear cells to release cytokines which initiate endotoxic effects. Interaction of LPS at low concentrations with target cells is CD14‐independent whereas at high LPS concentrations it is CD14‐independent. Here, we demonstrate by resonance energy transfer (RET) technique that nonspecific, CD14‐independent intercalation of LPS into membrane systems can be mediated by lipopolysaccharide‐binding protein (LBP). It is proposed that in this pathway, LBP breaks down LPS aggregates, transports the smaller units to and inserts them into the phospholipid cell matrix. We furthermore show that LBP also mediates the intercalation of other negatively charged amphiphilic molecules. We propose a model explaining CD14‐independent cell activation at high endotoxin concentrations.