Biomaterial Database

Localization of an immunologically functional region of the streptococcal superantigen pepsin-extracted fragment of type 5 M protein. 1993

B Wang, and P M Schlievert, and A O Gaber, and M Kotb

Veteran's Administration Medical Center, Memphis, TN 38104.

Ten overlapping synthetic peptides, spanning the entire amino acid sequence of pepsin-extracted type 5 M protein, (pep M5), were used to delineate regions within this molecule that are important for the mitogenic activity of this streptococcal superantigen. Two of the overlapping peptides, SM5-8 and SM5-10, blocked the response of T cells to pep M5 in a dose-dependent manner. Neither peptide was toxic to T cells, but SM5-8 exhibited nonspecific inhibition of the T-cell response to either superantigen or polyclonal mitogens. In contrast, the inhibition by SM5-10 was pep M5-specific. Analysis of TCR V beta gene usage of the pep M5 response in the presence and absence of SM5-10 revealed that this peptide preferentially blocks the expansion of pep M5-specific V beta elements. The degree of inhibition of V beta expansion varied from one individual to the other, reflecting their TCR repertoire. SM5-10 did not significantly inhibit the response of T cells to other streptococcal superantigens. The data suggest that the region represented by SM5-10 of the pep M5 is important for superantigenic activity. In addition, the ability of this synthetic peptide to inhibit the response to pep M5 provides evidence that the mitogenic response is indeed mediated by this superantigen and is not a result of contamination with other streptococcal superantigens.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010434	Pepsin A	Formed from pig pepsinogen by cleavage of one peptide bond. The enzyme is a single polypeptide chain and is inhibited by methyl 2-diaazoacetamidohexanoate. It cleaves peptides preferentially at the carbonyl linkages of phenylalanine or leucine and acts as the principal digestive enzyme of gastric juice.	Pepsin,Pepsin 1,Pepsin 3
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000938	Antigen-Presenting Cells	A heterogeneous group of immunocompetent cells that mediate the cellular immune response by processing and presenting antigens to the T-cells. Traditional antigen-presenting cells include MACROPHAGES; DENDRITIC CELLS; LANGERHANS CELLS; and B-LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS are not traditional antigen-presenting cells, but because they hold antigen on their cell surface in the form of IMMUNE COMPLEXES for B-cell recognition they are considered so by some authors.	Accessory Cells, Immunologic,Antigen-Presenting Cell,Immunologic Accessory Cells,Accessory Cell, Immunologic,Cell, Immunologic Accessory,Cells, Immunologic Accessory,Immunologic Accessory Cell,Antigen Presenting Cell,Antigen Presenting Cells,Cell, Antigen-Presenting,Cells, Antigen-Presenting
D000942	Antigens, Bacterial	Substances elaborated by bacteria that have antigenic activity.	Bacterial Antigen,Bacterial Antigens,Antigen, Bacterial
D001425	Bacterial Outer Membrane Proteins	Proteins isolated from the outer membrane of Gram-negative bacteria.	OMP Proteins,Outer Membrane Proteins, Bacterial,Outer Membrane Lipoproteins, Bacterial
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial