Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Epitopes are specific regions on an antigen that are recognized and bound by antibodies or T-cell receptors. They play a crucial role in the specificity of the immune response.
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Epitopes are also known as antigenic determinants.
A single antigen can have multiple epitopes, each capable of eliciting a different immune response.
B cells recognize epitopes through their surface immunoglobulins (antibodies), while T cells recognize them via T-cell receptors in conjunction with MHC molecules.
The binding of an epitope to its corresponding antibody is highly specific, much like a lock and key mechanism.
Linear epitopes consist of sequential amino acids, whereas conformational epitopes depend on the protein's three-dimensional structure.