Properdin

CFP
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1W0R, 1W0S
Identifiers
Aliases	CFP, BFD, PFC, PFD, PROPERDIN, complement factor properdin, properdin
External IDs	OMIM: 300383; MGI: 97545; HomoloGene: 1969; GeneCards: CFP; OMA:CFP - orthologs
Gene location (Human) Chr. X chromosome (human)[1] Band Xp11.23 Start 47,623,172 bp[1] End 47,630,305 bp[1]
Gene location (Mouse) Chr. X chromosome (mouse)[2] Band X A1.3|X 16.44 cM Start 20,791,693 bp[2] End 20,797,794 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in granulocyte monocyte blood spleen bone marrow bone marrow cells gonad appendix lymph node right lung Top expressed in granulocyte stroma of bone marrow spleen mesenteric lymph nodes ankle joint right lobe of liver axillary lymph node white adipose tissue tibiofemoral joint thymus More reference expression data BioGPS n/a
Gene ontology Molecular function protein binding serine-type endopeptidase activity Cellular component extracellular matrix endoplasmic reticulum lumen extracellular region extracellular space specific granule lumen tertiary granule lumen collagen-containing extracellular matrix Biological process immune response regulation of complement activation defense response to bacterium immune system process complement activation protein O-linked fucosylation complement activation, alternative pathway innate immune response neutrophil degranulation proteolysis Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 5199 18636 Ensembl ENSG00000126759 ENSMUSG00000001128 UniProt P27918 P11680 RefSeq (mRNA) NM_002621 NM_001145252 NM_008823 RefSeq (protein) NP_001138724 NP_002612 NP_032849 Location (UCSC) Chr X: 47.62 – 47.63 Mb Chr X: 20.79 – 20.8 Mb PubMed search [3] [4]
Wikidata
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Properdin is a protein that in humans is encoded by the CFP (complement factor properdin) gene.

Properdin is plasma glycoprotein that activates the complement system of the innate immune system. This protein binds to bacterial cell walls and dying human cells to stabilize the C3 and C5-convertase enzyme complexes to form an attack complex that lead to the lysis of the cell.

Properdin is a gamma globulin protein composed of multiple identical protein subunits with a separate ligand-binding site. Native properdin occurs in head-to-tail dimers, trimers and tetramers in the fixed ratio 22:52:28.^[5]

It is known that it participates in some specific immune responses. It plays a part in tissue inflammation as well as the engulfing of pathogens by phagocytes. In addition it is known to help to neutralize some viruses.

The properdin promotes the association of C3b with Factor B and provides a focal point for the assembly of C3bBb on a surface. It binds to preformed alternative pathway C3-convertases.^[6] Properdin also inhibits the Factor H – mediated cleavage of C3b by Factor I.

The alternative pathway is not dependent on antibodies. This branch of the complement system is activated by IgA immune complexes and bacterial endotoxins, polysaccharides, and cell walls, and results in producing anaphylatoxins, opsonins, chemotactic factors, and the membrane attack complex, all of which help fight pathogens.

Properdin was discovered in 1954 by Dr. Louis Pillemer of the Institute of Pathology (now the Department of Pathology at Case Western Reserve University).

Properdin deficiency is a rare X-linked disease in which properdin is deficient. Affected individuals are susceptible to fulminant meningococcal disease.^[7]

• Properdin at the U.S. National Library of Medicine Medical Subject Headings (MeSH)