scholarly journals Lipopolysaccharide-Binding Protein and Phospholipid Transfer Protein Release Lipopolysaccharides from Gram-Negative Bacterial Membranes

2000 ◽  
Vol 68 (5) ◽  
pp. 2410-2417 ◽  
Author(s):  
C. J. Vesy ◽  
R. L. Kitchens ◽  
G. Wolfbauer ◽  
J. J. Albers ◽  
R. S. Munford
Keyword(s):  
Human Serum ◽  
Binding Protein ◽  
Normal Human Serum ◽  
High Density Lipoproteins ◽  
Phospholipid Transfer Protein ◽  
Gram Negative ◽  
Bacterial Membranes ◽  
Transfer Protein ◽  
Phospholipid Transfer ◽  
Normal Human

ABSTRACT Although animals mobilize their innate defenses against gram-negative bacteria when they sense the lipid A moiety of bacterial lipopolysaccharide (LPS), excessive responses to this conserved bacterial molecule can be harmful. Of the known ways for decreasing the stimulatory potency of LPS in blood, the binding and neutralization of LPS by plasma lipoproteins is most prominent. The mechanisms by which host lipoproteins take up the native LPS that is found in bacterial membranes are poorly understood, however, since almost all studies of host-LPS interactions have used purified LPS aggregates. Using nativeSalmonella enterica serovar Typhimurium outer membrane fragments (blebs) that contained 3H-labeled lipopolysaccharide (LPS) and 35S-labeled protein, we found that two human plasma proteins, LPS-binding protein (LBP) and phospholipid transfer protein (PLTP), can extract [3H]LPS from bacterial membranes and transfer it to human high-density lipoproteins (HDL). Soluble CD14 (sCD14) did not release LPS from blebs yet could facilitate LBP-mediated LPS transfer to HDL. LBP, but not PLTP, also promoted the activation of human monocytes by bleb-derived LPS. Whereas depleting or neutralizing LBP significantly reduced LPS transfer from blebs to lipoproteins in normal human serum, neutralizing serum PLTP had no demonstrable effect. Of the known lipid transfer proteins, LBP is thus most able to transfer LPS from bacterial membranes to the lipoproteins in normal human serum.

scholarly journals Elevated Phospholipid Transfer Protein in Subjects with Multiple Sclerosis

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Roy A. Garvin
Keyword(s):  
Multiple Sclerosis ◽  
Structural Changes ◽  
Protein A ◽  
High Density Lipoproteins ◽  
Phospholipid Transfer Protein ◽  
Lipid Uptake ◽  
Myelin Lipid ◽  
Transfer Protein ◽  
Transfer Activity ◽  
Phospholipid Transfer

An anomaly in the plasma proteins of patients with multiple sclerosis detectable on SDS-PAGE has been reported. The molecular weight of the anomaly was the same as the phospholipid transfer protein. A metabolic protein was involved in lipid homeostasis and remodeling of the high density lipoproteins. We have identified the anomaly as the phospholipid transfer protein by western blot using antiphospholipid transfer antibodies. Activity assays showed that the phospholipid transfer activity was elevated in fasted plasma samples from subjects with MS compared to controls. Sequence analysis of the gene encoding the phospholipid transfer protein did not identify any mutations in the genetic structure, suggesting that the increase in activity was not due to structural changes in the protein, but may be due to one of the other proteins with which it forms active complexes. Altered phospholipid transfer activity is important because it could be implicated in the decreased lipid uptake and abnormal myelin lipids observed in multiple sclerosis. It has been shown that alteration in myelin lipid content is an epitope for autoimmunity. Therefore, lipid changes due to a defect in phospholipid transfer and/or uptake could potentially influence the course of the disease. Further research is needed to elucidate the role of the phospholipid transfer protein in subjects with multiple sclerosis.

Plasma phospholipid transfer protein and the anti-atherogenic potential of high density lipoproteins

2000 ◽  
Vol 151 (1) ◽  
pp. 182
Author(s):  
A. Van Tol ◽  
P.S. Vermeulen ◽  
M. Jauhiainen ◽  
R. Van Haperen ◽  
T. Van Gent ◽  
...  
Keyword(s):  
Plasma Phospholipid ◽  
High Density ◽  
High Density Lipoproteins ◽  
Phospholipid Transfer Protein ◽  
Transfer Protein ◽  
Phospholipid Transfer

scholarly journals Lipopolysaccharide Is Transferred from High-Density to Low-Density Lipoproteins by Lipopolysaccharide-Binding Protein and Phospholipid Transfer Protein

2005 ◽  
Vol 73 (4) ◽  
pp. 2321-2326 ◽  
Author(s):  
J. H. M. Levels ◽  
J. A. Marquart ◽  
P. R. Abraham ◽  
A. E. van den Ende ◽  
H. O. F. Molhuizen ◽  
...  
Keyword(s):  
Acute Phase ◽  
Binding Protein ◽  
Low Density Lipoproteins ◽  
High Density ◽  
Phospholipid Transfer Protein ◽  
Low Density ◽  
Lipoprotein Subclasses ◽  
Transfer Protein ◽  
Phospholipid Transfer ◽  
Dose Dependent

ABSTRACT Lipopolysaccharide (LPS), the major outer membrane component of gram-negative bacteria, is a potent endotoxin that triggers cytokine-mediated systemic inflammatory responses in the host. Plasma lipoproteins are capable of LPS sequestration, thereby attenuating the host response to infection, but ensuing dyslipidemia severely compromises this host defense mechanism. We have recently reported that Escherichia coli J5 and Re595 LPS chemotypes that contain relatively short O-antigen polysaccharide side chains are efficiently redistributed from high-density lipoproteins (HDL) to other lipoprotein subclasses in normal human whole blood (ex vivo). In this study, we examined the role of the acute-phase proteins LPS-binding protein (LBP) and phospholipid transfer protein (PLTP) in this process. By the use of isolated HDL containing fluorescent J5 LPS, the redistribution of endotoxin among the major lipoprotein subclasses in a model system was determined by gel permeation chromatography. The kinetics of LPS and lipid particle interactions were determined by using Biacore analysis. LBP and PLTP were found to transfer LPS from HDL predominantly to low-density lipoproteins (LDL), in a time- and dose-dependent manner, to induce remodeling of HDL into two subpopulations as a consequence of the LPS transfer and to enhance the steady-state association of LDL with HDL in a dose-dependent fashion. The presence of LPS on HDL further enhanced LBP-dependent interactions of LDL with HDL and increased the stability of the HDL-LDL complexes. We postulate that HDL remodeling induced by LBP- and PLTP-mediated LPS transfer may contribute to the plasma lipoprotein dyslipidemia characteristic of the acute-phase response to infection.

Abstract 127: Structure and Function Relationship of Phospholipid Transfer Protein in Lipid Transfer Activity Revealed by Electron Microscopy

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Meng Zhang
Keyword(s):  
Electron Microscopy ◽  
High Density Lipoproteins ◽  
Phospholipid Transfer Protein ◽  
Lipid Transfer ◽  
Transfer Protein ◽  
Phospholipid Transfer ◽  
Function Relationship ◽  
Structure And Function Relationship ◽  
And Function ◽  
Relationship Of

Human phospholipid transfer protein (PLTP) mediates the transfer of lipids among atheroprotective high-density lipoproteins (HDL) and atherogenic low-density lipoproteins (LDL) by an unknown mechanism. Delineating this mechanism would be an important step toward the understanding and regulation of PLTP for treating cardiovascular diseases, hypoalphalipoproteinemia and hyperalphalipoproteinemia. Using electron microscopy, negative-staining, and single-particle image processing, we discovered that PLTP penetrates each class of HDL, LDL and liposome independently, and also bridges a ternary complex with one of its distal end-domains penetrating into HDL and another distal domain interacting with LDL. These new insights into PLTP interaction with lipoproteins and liposomes provide a molecular basis for analyzing PLTP-dependent lipid transfer between lipoprotein particles.

scholarly journals The Mechanism of the Remodeling of High Density Lipoproteins by Phospholipid Transfer Protein

2001 ◽  
Vol 276 (29) ◽  
pp. 26898-26905 ◽  
Author(s):  
Nongnuch Settasatian ◽  
MyNgan Duong ◽  
Linda K. Curtiss ◽  
Christian Ehnholm ◽  
Matti Jauhiainen ◽  
...  
Keyword(s):  
High Density ◽  
High Density Lipoproteins ◽  
Phospholipid Transfer Protein ◽  
Transfer Protein ◽  
Phospholipid Transfer
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