Lipid binding protein BPI/LBP (IPR030675)

Short name: BPI/LBP

Overlapping homologous superfamilies


Family relationships


This entry represents the bactericidal permeability-increasing protein (BPI) and the lipopolysaccharide-binding protein (LBP). The crystal structures of BPI and LBP are similar [PMID: 9188532], and they may represent a common gene family of lipid-binding proteins [PMID: 9441745].

In mammals, LBP and BPI mediate the biological effects of LPS (lipopolysaccharide), a glycolipid present in the outer membrane of Gram-negative bacteria. LBP is a plasma protein that enhances the inflammatory response to LPS, whereas BPI is found in lysosomal granules of polymorphonuclear neutrophils, is bactericidal, and neutralises the toxic effects of LPS [PMID: 7613727, PMID: 7517398].

LBP is an acute phase serum protein secreted mainly by the liver that modulates the LPS-induced immune response. LBP binds mainly to the lipid A moiety of LPS and acts as an affinity enhancer for CD14, facilitating its association with LPS [PMID: 8834448].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0008289 lipid binding

Cellular Component

GO:0005615 extracellular space

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.