Lipid-binding serum glycoprotein explained

Symbol:LBP_BPI_CETP
LBP / BPI / CETP family, N-terminal domain
Pfam:PF01273
Interpro:IPR017942
Prosite:PDOC00367
Scop:1bp1
Tcdb:1.C.40
Opm Family:170
Opm Protein:2obd
Symbol:LBP_BPI_CETP_C
LBP / BPI / CETP family, C-terminal domain
Pfam:PF02886
Interpro:IPR001124
Prosite:PDOC00367
Scop:1bp1
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:

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]

Notes and References

  1. Gray PW, Flaggs G, Leong SR, Gumina RJ, Weiss J, Ooi CE, Elsbach P . Cloning of the cDNA of a human neutrophil bactericidal protein. Structural and functional correlations . J. Biol. Chem. . 264 . 16 . 9505–9509 . 1989 . 10.1016/S0021-9258(18)60560-5 . 2722846 . free .
  2. Gray PW, Leong SR, Wright SD, Schumann RR, Flaggs GW, Mathison JC, Tobias PS, Ulevitch RJ . Structure and function of lipopolysaccharide binding protein . Science . 249 . 4975 . 1429–1431 . 1990 . 2402637 . 10.1126/science.2402637. 1990Sci...249.1429S .
  3. Grant FJ, Day JR, Albers JJ, Lofton-Day CE, Gilbert TL, Marcovina SM, Adolphson JL, O Hara PJ, Ching AF . Complete cDNA encoding human phospholipid transfer protein from human endothelial cells . J. Biol. Chem. . 269 . 12 . 9388–9391 . 1994 . 10.1016/S0021-9258(17)37120-X . 8132678 . free .
  4. Beamer . LJ . Carroll . SF . Eisenberg . D . The BPI/LBP family of proteins: a structural analysis of conserved regions . Protein Science . 7 . 4 . 906–914 . April 1998 . 9568897 . 2143972 . 10.1002/pro.5560070408 .
  5. Beamer LJ, Carroll SF, Eisenberg D . Crystal structure of human BPI and two bound phospholipids at 2.4 angstrom resolution . Science . 276 . 5320 . 1861–4 . June 1997 . 9188532 . 10.1126/science.276.5320.1861.
  6. Kleiger G, Beamer LJ, Grothe R, Mallick P, Eisenberg D . 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 . 10843855 . 10.1006/jmbi.2000.3805 . 2392067 .
  7. Weiss J . 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 . August 2003 . 12887306 . 10.1042/bst0310785. 1155741 .
  8. Hamilton JA, Deckelbaum RJ . 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 . 17277799 . 10.1038/nsmb0207-95 . 22193394 .
  9. Ponsin G, Qu SJ, Fan HZ, Pownall HJ . 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 . 12693940 . 10.1021/bi027006g .
  10. Bartlett JA, Hicks BJ, Schlomann JM, Ramachandran S, Nauseef WM, McCray PB . PLUNC is a secreted product of neutrophil granules . J. Leukoc. Biol. . 83 . 5 . 1201–6 . May 2008 . 18245229 . 10.1189/jlb.0507302 . 19196781 . free .
  11. Zhou HD, Li GY, Yang YX, Li XL, Sheng SR, Zhang WL, Zhao J . 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 . 16364440 . 10.1016/j.molimm.2005.10.021 .
  12. Wu. Tongde. Huang. Julianne. Moore. Patrick J.. Little. Michael S.. Walton. William G.. Fellner. Robert C.. Alexis. Neil E.. Di. Y. Peter. Redinbo. Matthew R.. 2017-02-06. Identification of BPIFA1/SPLUNC1 as an epithelium-derived smooth muscle relaxing factor. Nature Communications. en. 8. 14118. 10.1038/ncomms14118. 28165446. 2041-1723. 5303822. 2017NatCo...814118W.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lipid-binding serum glycoprotein".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.