Lipopolysaccharide (LPS)-binding proteins BPI and LBP form different types of complexes with LPS.
Lipopolysaccharide (LPS)-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI) are closely related LPS-binding proteins whose binding to LPS has markedly different functional consequences. To gain better insight into the possible basis of these functional differences, the physical properties of LBP-LPS and BPI-LPS complexes have been compared in this study by sedimentation, light scattering, and fluorescence analyses. These studies reveal dramatic differences in the physical properties of LPS complexed to LBP versus BPI. They suggest that of the two proteins, only LBP can disperse LPS aggegates. However, BPI can enhance both the sedimentation velocity and apparent size of LPS aggregates while inhibiting LPS-LBP binding even at very low (1:40 to 1:20) BPI:LPS molar ratios.
Tobias
P S
PS
Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA. Tobias@scripps.edu
Soldau
K
K
Iovine
N M
NM
Elsbach
P
P
Weiss
J
J
D000209:Acute-Phase Proteins; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D006801:Humans; D008027:Light; D008070:Lipopolysaccharides / Q000378:metabolism*; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011485:Protein Binding; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D002352:Carrier Proteins; D016650:Fluorescein-5-isothiocyanate; D008070:Lipopolysaccharides; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D000099231:Lipopolysaccharide-Binding Protein; C021623:bactericidal permeability increasing protein