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Characterization of an IgA receptor from group B streptococci: specificity for serum IgA

Lindahl, Gunnar LU ; Åkerström, Bo LU ; Vaerman, Jean-Pierre and Stenberg, Lars LU (1990) In European Journal of Immunology 20(10). p.2241-2247
Abstract
Some strains of group B streptococci express a cell surface protein which binds IgA. This report describes some properties of such an IgA receptor and compares it with a previously described IgA receptor from group A streptococci. The group B receptor was released in an almost pure form from bacteria incubated at elevated pH, and could be isolated by IgA-Sepharose affinity chromatography. The sequence of the N-terminal 19 amino acid residues was unique. The receptor preferentially binds IgA of human origin, as shown in immunoblotting experiments with purified IgA from nine different species. The affinity constant of the purified receptor for serum IgA was determined to be 3.5 x 10(8) M-1, but for secretory IgA it was too low to allow... (More)
Some strains of group B streptococci express a cell surface protein which binds IgA. This report describes some properties of such an IgA receptor and compares it with a previously described IgA receptor from group A streptococci. The group B receptor was released in an almost pure form from bacteria incubated at elevated pH, and could be isolated by IgA-Sepharose affinity chromatography. The sequence of the N-terminal 19 amino acid residues was unique. The receptor preferentially binds IgA of human origin, as shown in immunoblotting experiments with purified IgA from nine different species. The affinity constant of the purified receptor for serum IgA was determined to be 3.5 x 10(8) M-1, but for secretory IgA it was too low to allow determination. This result indicates that secretory component and/or J chain interferes with the binding of IgA to this type of bacterial receptor, which may be one of the physiological functions of these polypeptides. A reduction in affinity was also observed for another complexed form of IgA, alpha 1-microglobulin-IgA. The group B receptor is antigenically unrelated to the IgA receptor from group A streptococci (protein Arp), but competitive inhibition experiments indicate that they bind to the same region in IgA. The implications of these findings, and the biological role of bacterial IgA receptors, are discussed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
European Journal of Immunology
volume
20
issue
10
pages
2241 - 2247
publisher
John Wiley & Sons
external identifiers
  • pmid:2242758
  • scopus:0025049758
ISSN
1521-4141
DOI
10.1002/eji.1830201013
language
English
LU publication?
yes
id
f6795c1d-19cb-4b34-b2ba-c507e71f8a67 (old id 1105116)
date added to LUP
2008-08-04 17:03:41
date last changed
2017-08-06 03:38:45
@article{f6795c1d-19cb-4b34-b2ba-c507e71f8a67,
  abstract     = {Some strains of group B streptococci express a cell surface protein which binds IgA. This report describes some properties of such an IgA receptor and compares it with a previously described IgA receptor from group A streptococci. The group B receptor was released in an almost pure form from bacteria incubated at elevated pH, and could be isolated by IgA-Sepharose affinity chromatography. The sequence of the N-terminal 19 amino acid residues was unique. The receptor preferentially binds IgA of human origin, as shown in immunoblotting experiments with purified IgA from nine different species. The affinity constant of the purified receptor for serum IgA was determined to be 3.5 x 10(8) M-1, but for secretory IgA it was too low to allow determination. This result indicates that secretory component and/or J chain interferes with the binding of IgA to this type of bacterial receptor, which may be one of the physiological functions of these polypeptides. A reduction in affinity was also observed for another complexed form of IgA, alpha 1-microglobulin-IgA. The group B receptor is antigenically unrelated to the IgA receptor from group A streptococci (protein Arp), but competitive inhibition experiments indicate that they bind to the same region in IgA. The implications of these findings, and the biological role of bacterial IgA receptors, are discussed.},
  author       = {Lindahl, Gunnar and Åkerström, Bo and Vaerman, Jean-Pierre and Stenberg, Lars},
  issn         = {1521-4141},
  language     = {eng},
  number       = {10},
  pages        = {2241--2247},
  publisher    = {John Wiley & Sons},
  series       = {European Journal of Immunology},
  title        = {Characterization of an IgA receptor from group B streptococci: specificity for serum IgA},
  url          = {http://dx.doi.org/10.1002/eji.1830201013},
  volume       = {20},
  year         = {1990},
}