Taxonomic distribution of proteins containing BPI2 domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing BPI2 domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Structure and function of the plasma phospholipid transfer protein.

Lagrost L, Desrumaux C, Masson D, Deckert V, Gambert P
Curr Opin Lipidol. 1998; 9: 203-9

Recent cloning and sequencing of plasma phospholipid transfer protein complementary DNA revealed that phospholipid transfer protein belongs to the lipid transfer/lipopolysaccharide binding protein family that includes the cholesteryl ester transfer protein, the bactericidal permeability increasing protein and the lipopolysaccharide-binding protein. In addition to structural similarities, members of the lipid transfer/lipopolysaccharide-binding protein family might share some common functional properties, and recent studies demonstrated that phospholipid transfer protein can act in several distinct metabolic processes. In particular, the molecular transfer of phospholipids, unesterified cholesterol, alpha-tocopherol and lipopolysaccharides by phospholipid transfer protein suggests that it might be involved both in lipoprotein metabolism and in antimicrobial defence, resulting in a growing interest in this protein.

The genomic organization of the genes for human lipopolysaccharide binding protein (LBP) and bactericidal permeability increasing protein (BPI) is highly conserved.

Hubacek JA, Buchler C, Aslanidis C, Schmitz G
Biochem Biophys Res Commun. 1997; 236: 427-30

We have determined the exon/intron organization of the human lipopolysaccharide binding protein (LBP) and bactericidal permeability increasing protein (BPI) genes. The LBP gene spans approximately 28.5 kb and is composed of 14 exons while the 31.5-kb-long BPI gene is composed of 15 exons. Comparison of the genomic organization of the LBP and BPI genes together with the genomic structures of the PLTP (phospholipid transfer protein) and CETP (cholesteryl ester transfer protein) genes, which all together constitute a gene family of functionally related proteins, revealed high homology with a remarkable conservation of exon/intron transitions. The exon/intron junctions of the LBP, BPI, and PLTP genes are almost identical, with most of the exons being of the same size. In addition, functional domains are conserved in these proteins. The C-terminal octapeptide important for CETP anchoring in lipoprotein particles is also present in LBP, BPI, and PLTP. The LPS binding motif in exons 3 and 4 has been retained in LBP and BPI. Our results indicate that the LBP, BPI, and PLTP genes, and probably the CETP gene, may have evolved from a common primordial gene and may share similar functional properties.

Structure and function of lipopolysaccharide binding protein.

Schumann RR, Leong SR, Flaggs GW, Gray PW, Wright SD, Mathison JC, Tobias PS, Ulevitch RJ
Science. 1990; 249: 1429-31

The primary structure of lipopolysaccharide binding protein (LBP), a trace plasma protein that binds to the lipid A moiety of bacterial lipopolysaccharides (LPSs), was deduced by sequencing cloned complementary DNA. LBP shares sequence identity with another LPS binding protein found in granulocytes, bactericidal/permeability-increasing protein, and with cholesterol ester transport protein of the plasma. LBP may control the response to LPS under physiologic conditions by forming high-affinity complexes with LPS that bind to monocytes and macrophages, which then secrete tumor necrosis factor. The identification of this pathway for LPS-induced monocyte stimulation may aid in the development of treatments for diseases in which Gram-negative sepsis or endotoxemia are involved.

Cloning of the cDNA of a human neutrophil bactericidal protein. Structural and functional correlations.

Gray PW, Flaggs G, Leong SR, Gumina RJ, Weiss J, Ooi CE, Elsbach P
J Biol Chem. 1989; 264: 9505-9

The bactericidal permeability increasing protein (BPI) is a 50-60-kDa membrane-associated protein isolated from granules of polymorphonuclear leukocytes. A full-length cDNA clone encoding human BPI has been isolated and the derived amino acid sequence reveals a structure that is consistent with previously determined biological properties. BPI may be organized into two domains: the amino-terminal half, previously shown to contain all known antimicrobial activity, contains a large fraction of basic and hydrophilic residues. In contrast, the carboxyl-terminal half contains more acidic than basic residues and includes several potential transmembrane regions which may anchor the holoprotein in the granule membrane. The cytotoxic action of BPI is limited to many species of Gram-negative bacteria; this specificity may be explained by a strong affinity of the very basic aminoterminal half for the negatively charged lipopolysaccharides that are unique to the Gram-negative bacterial envelope. The amino-terminal end of BPI exhibits significant similarity with the sequence of a rabbit lipopolysaccharide-binding protein, suggesting that both molecules share a similar structure for binding lipopolysaccharides.