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a factor that establishes the nature of an entity or event.
antigenic determinant a site on the surface of an antigen molecule to which a single antibody molecule binds; generally an antigen has several or many different antigenic determinants and reacts with many different antibodies. Called also epitope.
hidden determinant an antigenic determinant located in an unexposed region of a molecule so that it is prevented from interacting with receptors on lymphocytes, or with antibody molecules, and is unable to induce an immune response; it may appear following stereochemical alterations of molecular structure.
immunogenic determinant the part of an immunogenic molecule that interacts with a helper T cell in triggering antibody production as opposed to the antigenic determinant or hapten, which interacts with B cells.
The simplest form of an antigenic determinant on a complex antigenic molecule, which can combine with antibody or T cell receptor.
[epi- + -tope]
epitope/ep·i·tope/ (ep´ĭ-tōp) an antigenic determinant (see under determinant ) of known structure.
A localized region on the surface of an antigen capable of eliciting an immune response and of combining with a specific antibody to counter that response.
Etymology: Gk epi + topos, place
epitopeAny site on a biomolecule (antigenic determinant) which can evoke antibody formation. The minimum size of a molecule capable of evoking antibody formation is about 1 kD; if the molecule is smaller, as with haptens, it may evoke an immune response by associating with a carrier protein. Large non-polymeric molecules can have many epitopes. When the van der Waals surfaces of proteins are constructed by X-ray crystallography, epitopic sites appear to require prominently exposed regions—“hills” and “ridges” with surface rigidity. More flexible sites are less antigenic.
epitopeImmunology Any site on a molecule–an antigenic determinant that can evoke antibody formation. See Idiotype, Immunogenicity.
The simplest form of an antigenic determinant, on a complex antigenic molecule, that can combine with antibody or T-cell receptor.
epitopeAn immunologically active discrete site on an ANTIGEN to which an ANTIBODY or a B or T cell receptor actually binds. See also LINEAR EPITOPE and CONFORMATIONAL EPITOPE.
epitopean antigenic determinant which interacts with an IMMUNOGLOBULIN or T-CELL receptor.
see antigenic determinant.
contiguous amino acid sequences in a linear array.
one in which amino acids are in close proximity in the folded protein, but distant when unfolded.