Identification of the Complement iC3b Binding Site in the β2 Integrin CR3 (CD11b/CD18)

The divalent cation-dependent interaction of the β 2 integrin CR3 (CD11b/CD18) with the major complement opsonic C3 fragment iC3b is an important component of the central role of CR3 in inflammation and immune clearance. In this investigation we have identified the iC3b binding site in CR3. A recomb...

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Bibliographic Details
Published inProceedings of the National Academy of Sciences - PNAS Vol. 91; no. 22; pp. 10680 - 10684
Main Authors Ueda, Takeo, Rieu, Philippe, Brayer, James, Arnaout, M. Amin
Format Journal Article
LanguageEnglish
Published National Academy of Sciences of the United States of America 25.10.1994
Subjects
Amino acids
Binding sites
Divalent cations
Goods and services tax
Histograms
Integrins
Ligands
Neutrophils
Proteins
Temperature dependence
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Summary:The divalent cation-dependent interaction of the β 2 integrin CR3 (CD11b/CD18) with the major complement opsonic C3 fragment iC3b is an important component of the central role of CR3 in inflammation and immune clearance. In this investigation we have identified the iC3b binding site in CR3. A recombinant fragment representing the CR3 A-do-main, a 200-amino acid region in the ectodomain of the CD11b subunit, bound to iC3b directly and in a divalent cation-dependent manner. The iC3b binding site was further localized to a short linear peptide that also bound iC3b directly and inhibited iC3b binding to the A-domain as well as to CR3 expressed by human neutrophils. These data establish a major recognition function for the integrin A-domain and have important implications for development of novel antiinflammatory therapeutics.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.91.22.10680