Complement component 5 is a protein that in humans is encoded by the C5 gene.[5]
C5 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Aliases | C5, C5D, C5a, C5b, CPAMD4, ECLZB, complement component 5, complement C5 | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | OMIM: 120900 MGI: 96031 HomoloGene: 20412 GeneCards: C5 | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Complement component 5 is involved in the complement system. It is cleaved into C5a and C5b:
Deficiency is thought to cause Leiner's disease.
Complement component 5 is the fifth component of complement, which plays an important role in inflammatory and cell killing processes. This protein is composed of alpha and beta polypeptide chains that are linked by a disulfide bridge. An activation peptide, C5a, which is an anaphylatoxin that possesses potent spasmogenic and chemotactic activity, is derived from the alpha polypeptide via cleavage with a C5-convertase. The C5b macromolecular cleavage product can form a complex with the C6 complement component, and this complex is the basis for formation of the membrane attack complex, which includes additional complement components.[5]
Mutations in this gene cause complement component 5 deficiency, a disease where patients show a propensity for severe recurrent infections. Defects in this gene have also been linked to a susceptibility to liver fibrosis and to rheumatoid arthritis.[5]
The drug eculizumab (trade name Soliris) prevents cleavage of C5 into C5a and C5b.[7]
This article incorporates text from the United States National Library of Medicine, which is in the public domain.