lipid-binding serum glycoprotein

These proteins consist of N- and C-terminal domains, which share a similar two-layer alpha/beta structure, but show little sequence identity to each other. These domains were first described as being arranged in a "boomerang" shape that creates the BPI fold.{{cite journal |

last1=Beamer | first1=LJ | last2=Carroll | first2=SF | last3=Eisenberg | first3=D | title = The BPI/LBP family of proteins: a structural analysis of conserved regions | journal = Protein Science | volume = 7 | issue = 4 | pages = 906–914 | date = April 1998 | pmid = 9568897 | pmc = 2143972 | doi = 10.1002/pro.5560070408 }} The fold contains apolar binding pockets that can interact with hydrophobic and amphipathic molecules, such as the acyl carbon chains of lipopolysaccharide found on Gram-negative bacteria.

Bactericidal permeability-increasing protein (BPI) is a potent antimicrobial protein of 456 amino acids that binds to and neutralises lipopolysaccharides from the outer membrane of Gram-negative bacteria.{{cite journal |vauthors=Beamer LJ, Carroll SF, Eisenberg D | title = Crystal structure of human BPI and two bound phospholipids at 2.4 angstrom resolution | journal = Science | volume = 276 | issue = 5320 | pages = 1861–4 |date=June 1997 | pmid = 9188532 | doi = 10.1126/science.276.5320.1861}} BPI contains two domains that adopt the same structural fold, even though they have little sequence similarity.{{cite journal |vauthors=Kleiger G, Beamer LJ, Grothe R, Mallick P, Eisenberg D | title = The 1.7 A crystal structure of BPI: a study of how two dissimilar amino acid sequences can adopt the same fold | journal = J. Mol. Biol. | volume = 299 | issue = 4 | pages = 1019–34 |date=June 2000 | pmid = 10843855 | doi = 10.1006/jmbi.2000.3805 | s2cid = 2392067 }}

Lipopolysaccharide-binding protein (LBP) is an endotoxin-binding protein that is closely related to, and functions in a co-ordinated manner with BPI to facilitate an integrated host response to invading Gram-negative bacteria.{{cite journal | author = Weiss J | title = Bactericidal/permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP): structure, function and regulation in host defence against Gram-negative bacteria | journal = Biochem. Soc. Trans. | volume = 31 | issue = Pt 4 | pages = 785–90 |date=August 2003 | pmid = 12887306 | doi = 10.1042/bst0310785| s2cid = 1155741 }}

Cholesteryl ester transfer protein (CETP) is a glycoprotein that facilitates the transfer of lipids (cholesteryl esters and triglycerides) between the different lipoproteins that transport them through plasma, including HDL, LDL, VLDL and chylomicrons. These lipoproteins shield the lipids from water by encapsulating them within a coating of polar lipids and proteins.{{cite journal |vauthors=Hamilton JA, Deckelbaum RJ | title = Crystal structure of CETP: new hopes for raising HDL to decrease risk of cardiovascular disease? | journal = Nat. Struct. Mol. Biol. | volume = 14 | issue = 2 | pages = 95–7 |date=February 2007 | pmid = 17277799 | doi = 10.1038/nsmb0207-95 | s2cid = 22193394 }}

Phospholipid transfer protein (PLTP) exchanges phospholipids between lipoproteins and remodels high-density lipoproteins (HDLs).{{cite journal |vauthors=Ponsin G, Qu SJ, Fan HZ, Pownall HJ | title = Structural and functional determinants of human plasma phospholipid transfer protein activity as revealed by site-directed mutagenesis of charged amino acids | journal = Biochemistry | volume = 42 | issue = 15 | pages = 4444–51 |date=April 2003 | pmid = 12693940 | doi = 10.1021/bi027006g }}

Palate, lung and nasal epithelium carcinoma-associated protein (PLUNC) is a potential host defensive protein that is secreted from the submucosal gland to the saliva and nasal lavage fluid. PLUNC appears to be a secreted product of neutrophil granules that participates in an aspect of the inflammatory response that contributes to host defence.{{cite journal |vauthors=Bartlett JA, Hicks BJ, Schlomann JM, Ramachandran S, Nauseef WM, McCray PB | title = PLUNC is a secreted product of neutrophil granules | journal = J. Leukoc. Biol. | volume = 83 | issue = 5 | pages = 1201–6 |date=May 2008 | pmid = 18245229 | doi = 10.1189/jlb.0507302 | s2cid = 19196781 | doi-access = free }}

Short palate, lung and nasal epithelium clone 1 (SPLUNC1) may bind the lipopolysaccharide of Gram-negative nanobacteria, thereby playing an important role in the host defence of nasopharyngeal epithelium.{{cite journal |vauthors=Zhou HD, Li GY, Yang YX, Li XL, Sheng SR, Zhang WL, Zhao J | title = Intracellular co-localization of SPLUNC1 protein with nanobacteria in nasopharyngeal carcinoma epithelia HNE1 cells depended on the bactericidal permeability increasing protein domain | journal = Mol. Immunol. | volume = 43 | issue = 11 | pages = 1864–71 |date=April 2006 | pmid = 16364440 | doi = 10.1016/j.molimm.2005.10.021 }}

Bacterial permeability family member A1 (BPIFA1/SPLUNC1) is an innate protein that is secreted basolaterally from healthy, but not asthmatic, human bronchial epithelial cultures (HBECs). It suppresses airway smooth muscle contractility by binding to and inhibiting the Ca2+ influx channel Orai1.{{Cite journal|last1=Wu|first1=Tongde|last2=Huang|first2=Julianne|last3=Moore|first3=Patrick J.|last4=Little|first4=Michael S.|last5=Walton|first5=William G.|last6=Fellner|first6=Robert C.|last7=Alexis|first7=Neil E.|last8=Di|first8=Y. Peter|last9=Redinbo|first9=Matthew R.|date=2017-02-06|title=Identification of BPIFA1/SPLUNC1 as an epithelium-derived smooth muscle relaxing factor|journal=Nature Communications|language=en|volume=8|pages=14118|doi=10.1038/ncomms14118|pmid=28165446|issn=2041-1723|pmc=5303822|bibcode=2017NatCo...814118W}}

{{unbulleted list

| Bactericidal permeability-increasing protein (BPI)

| BPI fold-containing family A member 1 (BPIFA1, PLUNC, SPLUNC1, SPURT)

| BPI fold-containing family A member 2 (BPIFA2, SPLUNC2)

| BPI fold-containing family A member 3 (BPIFA3, SPLUNC3)

| BPI fold-containing family B member 1 (BPIFB1, LPLUNC1)

| BPI fold-containing family B member 2 (BPIFB2, LPLUNC2, BPIL1)

| BPI fold-containing family B member 3 (BPIFB3, LPLUNC3)

| BPI fold-containing family B member 4 (BPIFB4, LPLUNC4)

| BPI fold-containing family B member 6 (BPIFB6, LPLUNC6, BPIL3)

| BPI fold-containing family C protein (BPIFC, BPIL2),{{cite web |title=Q8NFQ6 - BPIFC_HUMAN |url=https://www.uniprot.org/uniprotkb/Q8NFQ6/entry |website=www.uniprot.org}}

| Cholesteryl ester transfer protein

| Latherin (LATH, BPIFA4P){{cite web |title=Q86YQ2 - LATH_HUMAN |url=https://www.uniprot.org/uniprotkb/Q86YQ2/entry |website=www.uniprot.org}}

| Lipopolysaccharide-binding protein (LBP)

| Phospholipid transfer protein (PLTP)

|}}

{{reflist}}

{{InterPro content|IPR017942}}

{{InterPro content|IPR001124}}

{{DEFAULTSORT:Lipid-Binding Serum Glycoprotein}}

Category:Protein domains

Category:Protein families

Category:Peripheral membrane proteins

Category:Water-soluble transporters