Molecular characterization of protein Sir, a streptococcal cell surface protein that binds both immunoglobulin A and immunoglobulin G
(1994) In Journal of Biological Chemistry 269(18). p.13458-13464- Abstract
- Cell surface proteins that bind to the Fc part of immunoglobulin (Ig) A and/or IgG are expressed by many strains of the group A Streptococcus, an important human pathogen. Two extensively characterized proteins in this group of molecules are protein Arp that preferentially binds IgA and protein H that binds IgG. In addition, recent work has shown that many group A streptococcal strains express a novel type of Fc-binding protein, designated protein Sir, that binds both IgA and IgG. Protein Sir22, the molecule expressed by a strain of serotype M22, has now been purified and characterized after expression of the cloned gene in Escherichia coli. Dot-blot analysis with a large number of purified monoclonal Igs showed that protein Sir22 reacted... (More)
- Cell surface proteins that bind to the Fc part of immunoglobulin (Ig) A and/or IgG are expressed by many strains of the group A Streptococcus, an important human pathogen. Two extensively characterized proteins in this group of molecules are protein Arp that preferentially binds IgA and protein H that binds IgG. In addition, recent work has shown that many group A streptococcal strains express a novel type of Fc-binding protein, designated protein Sir, that binds both IgA and IgG. Protein Sir22, the molecule expressed by a strain of serotype M22, has now been purified and characterized after expression of the cloned gene in Escherichia coli. Dot-blot analysis with a large number of purified monoclonal Igs showed that protein Sir22 reacted with 19 out of 20 IgA proteins and with 19 out of 24 IgG proteins. The affinity constants for the reactions between protein Sir22 and Ig were determined to be 7.0 x 10(8) M-1 for serum IgA, 2.4 x 10(8 M-1 for secretory IgA, and 7.8 x 10(8) M-1 for IgG. Inhibition experiments showed that the bindings of IgA and IgG to protein Sir22 were mutually exclusive, indicating shared or contiguous binding sites. Analysis of the sequence of the sir22 gene indicated a gene product with 365 amino acid residues, including a 41-residue signal peptide. The processed form of the protein, 324 residues, has a calculated M(r) of 37,168. Deletion analysis of the sir22 gene showed that a 156-residue NH2-terminal fragment of protein Sir22 retained the ability to bind both IgA and IgG. The overall organization of protein Sir22 is similar to that of the IgA-binding protein Arp and the IgG-binding protein H. All three of these proteins are members of the M protein family and have a central repeat region of the C type. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1107967
- author
- Stenberg, Lars LU ; O'Toole, P W ; Mestecky, J and Lindahl, Gunnar LU
- organization
- publishing date
- 1994
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Biological Chemistry
- volume
- 269
- issue
- 18
- pages
- 13458 - 13464
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- pmid:8175778
- scopus:0028225870
- ISSN
- 1083-351X
- language
- English
- LU publication?
- yes
- id
- e42b4b75-aca6-4d26-b74e-8d8c8b2e5134 (old id 1107967)
- alternative location
- http://www.jbc.org/cgi/reprint/269/18/13458
- date added to LUP
- 2016-04-01 12:15:48
- date last changed
- 2021-03-28 06:18:03
@article{e42b4b75-aca6-4d26-b74e-8d8c8b2e5134,
abstract = {{Cell surface proteins that bind to the Fc part of immunoglobulin (Ig) A and/or IgG are expressed by many strains of the group A Streptococcus, an important human pathogen. Two extensively characterized proteins in this group of molecules are protein Arp that preferentially binds IgA and protein H that binds IgG. In addition, recent work has shown that many group A streptococcal strains express a novel type of Fc-binding protein, designated protein Sir, that binds both IgA and IgG. Protein Sir22, the molecule expressed by a strain of serotype M22, has now been purified and characterized after expression of the cloned gene in Escherichia coli. Dot-blot analysis with a large number of purified monoclonal Igs showed that protein Sir22 reacted with 19 out of 20 IgA proteins and with 19 out of 24 IgG proteins. The affinity constants for the reactions between protein Sir22 and Ig were determined to be 7.0 x 10(8) M-1 for serum IgA, 2.4 x 10(8 M-1 for secretory IgA, and 7.8 x 10(8) M-1 for IgG. Inhibition experiments showed that the bindings of IgA and IgG to protein Sir22 were mutually exclusive, indicating shared or contiguous binding sites. Analysis of the sequence of the sir22 gene indicated a gene product with 365 amino acid residues, including a 41-residue signal peptide. The processed form of the protein, 324 residues, has a calculated M(r) of 37,168. Deletion analysis of the sir22 gene showed that a 156-residue NH2-terminal fragment of protein Sir22 retained the ability to bind both IgA and IgG. The overall organization of protein Sir22 is similar to that of the IgA-binding protein Arp and the IgG-binding protein H. All three of these proteins are members of the M protein family and have a central repeat region of the C type.}},
author = {{Stenberg, Lars and O'Toole, P W and Mestecky, J and Lindahl, Gunnar}},
issn = {{1083-351X}},
language = {{eng}},
number = {{18}},
pages = {{13458--13464}},
publisher = {{American Society for Biochemistry and Molecular Biology}},
series = {{Journal of Biological Chemistry}},
title = {{Molecular characterization of protein Sir, a streptococcal cell surface protein that binds both immunoglobulin A and immunoglobulin G}},
url = {{http://www.jbc.org/cgi/reprint/269/18/13458}},
volume = {{269}},
year = {{1994}},
}