Biomaterial Database

Site of nonrestrictive binding of SEA to class II MHC antigens. 1990

C H Pontzer, and J K Russell, and M A Jarpe, and H M Johnson

Department of Microbiology and Cell Science, University of Florida, Gainesville.

We have used the synthetic peptide approach to show that the N-terminal 45-amino acids of staphylococcal enterotoxin A (SEA), SEA(1-45), constitute an important part of its binding site on class II major histocompatibility complex (MHC) molecules. SEA(1-45) and to a lesser extent SEA(1-27) were able to displace SEA from HLA-DR on Raji cells as assessed by flow cytometry and to compete with radiolabeled SEA for interaction with HLA-DR in a direct binding assay. Specific binding of SEA to Ia on murine A-20 cells could be inhibited by the same peptides [i.e. SEA(1-45) greater than SEA(1-27)] that blocked binding to HLA-DR. Therefore, different class II MHC molecules associate with the same functional site on SEA. Further, an ELISA system was used to demonstrate that SEA(1-45) is able to directly bind to a mouse synthetic I-A beta b peptide, I-A beta b (65-85), which contains a binding site of the class II MHC molecule involved in SEA presentation to T cells. Thus, we have localized a site on SEA that is involved in selective surface association with class II MHC antigens and identified the region on the class II MHC antigen to which that site binds.

UI	MeSH Term	Description	Entries
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D004768	Enterotoxins	Substances that are toxic to the intestinal tract causing vomiting, diarrhea, etc.; most common enterotoxins are produced by bacteria.	Staphylococcal Enterotoxin,Enterotoxin,Staphylococcal Enterotoxins,Enterotoxin, Staphylococcal,Enterotoxins, Staphylococcal
D006684	HLA-DR Antigens	A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.	HLA-DR,Antigens, HLA-DR,HLA DR Antigens
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D013211	Staphylococcus aureus	Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications.
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus