Biology:Lipid-binding serum glycoprotein
| LBP / BPI / CETP family, N-terminal domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 crystal structure of bpi, the human bactericidal permeability-increasing protein | |||||||||
| Identifiers | |||||||||
| Symbol | LBP_BPI_CETP | ||||||||
| Pfam | PF01273 | ||||||||
| InterPro | IPR017942 | ||||||||
| PROSITE | PDOC00367 | ||||||||
| SCOP2 | 1bp1 / SCOPe / SUPFAM | ||||||||
| TCDB | 1.C.40 | ||||||||
| OPM superfamily | 170 | ||||||||
| OPM protein | 2obd | ||||||||
| |||||||||
| LBP / BPI / CETP family, C-terminal domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
crystal structure of bpi, the human bactericidal permeability-increasing protein | |||||||||
| Identifiers | |||||||||
| Symbol | LBP_BPI_CETP_C | ||||||||
| Pfam | PF02886 | ||||||||
| InterPro | IPR001124 | ||||||||
| PROSITE | PDOC00367 | ||||||||
| SCOP2 | 1bp1 / SCOPe / SUPFAM | ||||||||
| TCDB | 1.C.40 | ||||||||
| |||||||||
In molecular biology, the lipid-binding serum glycoproteins family, also known as the BPI/LBP/Plunc family or LBP/BPI/CETP family represents a family which includes mammalian lipid-binding serum glycoproteins and/or proteins containing a structural motif known as the BPI fold. Members of this family include:
- Bactericidal permeability-increasing protein (BPI)[1]
- Lipopolysaccharide-binding protein (LBP)[2]
- Cholesteryl ester transfer protein (CETP)
- Phospholipid transfer protein (PLTP)[3]
- Palate, lung and nasal epithelium carcinoma-associated protein (PLUNC)
Structure
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.[4] 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.
Function
Bactericidal permeability-increasing protein
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.[5] BPI contains two domains that adopt the same structural fold, even though they have little sequence similarity.[6]
Lipopolysaccharide-binding protein
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.[7]
Cholesteryl ester transfer protein
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.[8]
Phospholipid transfer protein
Phospholipid transfer protein (PLTP) exchanges phospholipids between lipoproteins and remodels high-density lipoproteins (HDLs).[9]
Palate, lung and nasal epithelium carcinoma-associated protein
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.[10]
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.[11]
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.[12]
Human proteins belonging to this family
- 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),[13]
- Cholesteryl ester transfer protein
- Latherin (LATH, BPIFA4P)[14]
- Lipopolysaccharide-binding protein (LBP)
- Phospholipid transfer protein (PLTP)
References
- ↑ "Cloning of the cDNA of a human neutrophil bactericidal protein. Structural and functional correlations". J. Biol. Chem. 264 (16): 9505–9509. 1989. doi:10.1016/S0021-9258(18)60560-5. PMID 2722846.
- ↑ "Structure and function of lipopolysaccharide binding protein". Science 249 (4975): 1429–1431. 1990. doi:10.1126/science.2402637. PMID 2402637. Bibcode: 1990Sci...249.1429S.
- ↑ "Complete cDNA encoding human phospholipid transfer protein from human endothelial cells". J. Biol. Chem. 269 (12): 9388–9391. 1994. doi:10.1016/S0021-9258(17)37120-X. PMID 8132678.
- ↑ Beamer, LJ; Carroll, SF; Eisenberg, D (April 1998). "The BPI/LBP family of proteins: a structural analysis of conserved regions". Protein Science 7 (4): 906–914. doi:10.1002/pro.5560070408. PMID 9568897.
- ↑ "Crystal structure of human BPI and two bound phospholipids at 2.4 angstrom resolution". Science 276 (5320): 1861–4. June 1997. doi:10.1126/science.276.5320.1861. PMID 9188532.
- ↑ "The 1.7 A crystal structure of BPI: a study of how two dissimilar amino acid sequences can adopt the same fold". J. Mol. Biol. 299 (4): 1019–34. June 2000. doi:10.1006/jmbi.2000.3805. PMID 10843855.
- ↑ Weiss J (August 2003). "Bactericidal/permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP): structure, function and regulation in host defence against Gram-negative bacteria". Biochem. Soc. Trans. 31 (Pt 4): 785–90. doi:10.1042/bst0310785. PMID 12887306.
- ↑ "Crystal structure of CETP: new hopes for raising HDL to decrease risk of cardiovascular disease?". Nat. Struct. Mol. Biol. 14 (2): 95–7. February 2007. doi:10.1038/nsmb0207-95. PMID 17277799.
- ↑ "Structural and functional determinants of human plasma phospholipid transfer protein activity as revealed by site-directed mutagenesis of charged amino acids". Biochemistry 42 (15): 4444–51. April 2003. doi:10.1021/bi027006g. PMID 12693940.
- ↑ "PLUNC is a secreted product of neutrophil granules". J. Leukoc. Biol. 83 (5): 1201–6. May 2008. doi:10.1189/jlb.0507302. PMID 18245229.
- ↑ "Intracellular co-localization of SPLUNC1 protein with nanobacteria in nasopharyngeal carcinoma epithelia HNE1 cells depended on the bactericidal permeability increasing protein domain". Mol. Immunol. 43 (11): 1864–71. April 2006. doi:10.1016/j.molimm.2005.10.021. PMID 16364440.
- ↑ Wu, Tongde; Huang, Julianne; Moore, Patrick J.; Little, Michael S.; Walton, William G.; Fellner, Robert C.; Alexis, Neil E.; Di, Y. Peter et al. (2017-02-06). "Identification of BPIFA1/SPLUNC1 as an epithelium-derived smooth muscle relaxing factor" (in en). Nature Communications 8: 14118. doi:10.1038/ncomms14118. ISSN 2041-1723. PMID 28165446. Bibcode: 2017NatCo...814118W.
- ↑ "Q8NFQ6 - BPIFC_HUMAN". https://www.uniprot.org/uniprotkb/Q8NFQ6/entry.
- ↑ "Q86YQ2 - LATH_HUMAN". https://www.uniprot.org/uniprotkb/Q86YQ2/entry.
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