Lipopolysaccharide‐binding protein mediates CD14‐independent intercalation of lipopolysaccharide into phospholipid membranes

FEBS Letters

Rietschel, Ernst Th.¹  Brandenburg, Klaus¹  Carroll, Stephen F.²  Seydel, Ulrich¹  Flad, Hans-Dieter¹  Schromm, Andra B.¹ 

[1] Research Center Borstel, Center for Medicine and Biosciences, Parkallee 10, D-23845 Borstel, Germany;XOMA Corporation, 2910 Seventh Street, Berkeley, CA 94710, USA

关键词: LBP;    Endotoxin;    Bactericidal/permeability-increasing protein;    Nonspecific intercalation;    Phospholipid membrane;    BPI;    bactericidal/permeability-increasing protein;    BSA;    bovine serum albumim;    CAC;    critical aggregate concentration;    LBP;    lipopolysaccharide-binding protein;    LPS;    lipopolysaccharide endotoxin;    NBD-PE;    N-(7-nitro-2;    1;    3-benzoxadiazol-4-yl)-phosphatidylethanolamine;    PE;    phosphatidylethanolamine;    PLMbagohin;    mixture resembling the phospholipid matrix of a macrophage membrane;    RET;    resonance energy transfer;    Rh-PE;    N-(rhodamine B sulfonyl)phosphatidylethanolamine;   

DOI  :  10.1016/S0014-5793(96)01338-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown