Lipopolysaccharide binding protein

Lipopolysaccharide binding protein (LBP, LPS-binding protein) is a serum glycoprotein belonging to the family of lipid-binding proteins. LBP is synthesized by hepatocytes and intestinal epithelial cells, and is involved in the acute-phase immunologic response to gram-negative bacterial infections. Gram-negative bacteria contain a glycolipid, lipopolysaccharide (LPS), on their outer cell wall. Together with bactericidal permeability-increasing protein (BPI), LBP binds LPS and interacts with the CD14 receptor, playing a role in regulating LPS-dependent monocyte responses. Serum concentrations of LBP range between 5 and 10 ug/ml during homeostasis, increasing up to 200 ug/ml during the acute-phase response in the course of infection. Studies in mice suggest that the encoded protein is necessary for the rapid acute-phase response to LPS but not for the clearance of LPS from circulation. This protein is part of a family of structurally and functionally related proteins, including BPI, plasma cholesteryl ester transfer protein (CETP), and phospholipid transfer protein (PLTP).

Swiss-Prot Accession Number: P18428