Localization of binding sites of staphylococcal enterotoxin B (SEB), a superantigen, for HLA-DR by inhibition with synthetic peptides of SEB
| Autor: | Jeenan Tseng, J L Komisar, S Small-Harris |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
T-Lymphocytes
Immunology Molecular Sequence Data Peptide chemical and pharmacologic phenomena Enterotoxin In Vitro Techniques Major histocompatibility complex Microbiology Binding Competitive Enterotoxins Structure-Activity Relationship Tumor Cells Cultured Humans Amino Acid Sequence Binding site Peptide sequence HLA-DR Antigen chemistry.chemical_classification MHC class II Binding Sites Superantigens biology hemic and immune systems HLA-DR Antigens Molecular biology biological factors Infectious Diseases chemistry Biotinylation biology.protein Parasitology Peptides Research Article |
| Zdroj: | Infection and immunity. 62(11) |
| ISSN: | 0019-9567 |
| Popis: | Staphylococcal enterotoxins are major causes of food poisoning and toxic shock syndrome. Their ability to bind to major histocompatibility complex (MHC) class II molecules has been suggested to be the first step in the mechanism whereby they cause illness. By flow cytometric analysis, the sites of interaction of staphylococcal enterotoxin B (SEB) with HLA-DR molecules were probed in the present study by inhibiting the binding of biotinylated SEB to a human T-cell line (HUT-78) with synthetic peptides of SEB. Five peptides of SEB gave significant inhibition of binding: a peptide containing amino acids 9 to 20 [SEB(9-20)], SEB(30-38), SEB(61-70), SEB(90-114), and SEB(169-181). One peptide, SEB(39-51), enhanced binding. Among the inhibitory peptides, SEB(90-114), a peptide spanning the entire disulfide loop, showed the most efficient inhibition of binding. Peptides SEB(9-20) and SEB(39-51) include amino acid residues that have been identified by previous mutation studies (J.W. Kappler, A. Herman, J. Clements, and P. Marrack, J. Exp. Med. 175:387-396, 1992) as being important in binding to MHC class II. Amino acids lining the alpha 5 groove of SEB have also been postulated to be involved in binding to MHC class II molecules. However, only two of the residues that line the alpha 5 groove of SEB, His-12 and Tyr-17, are on peptide SEB(9-20) that inhibits binding. These results confirm previous studies that implicated the amino-terminal portion of the molecule in binding to MHC class II molecules and further indicate an important role for residues in other regions, particularly the disulfide loop. |
| Databáze: | OpenAIRE |
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