Antigenic determinants or Epitopes

ANTIGENIC DETERMINATS OR EPITOPES

  • An antigen will evoke immune response in a specific host.
  • The antigenic specificity is determined by Epitopes, the smallest unit of antigenicity.
  • Epitopes are some specific areas or chemical groupings with steric (spatial) configuration present on the surface of antigen molecule.
  • Epitopes are capable of sensitizing an immunocyte and reacting with its complementary site on the specific antibody or TCR.
  • The combining area on the hypervariable region of antibody molecule that corresponds to epitopes is called paratope or idiotope. On T cells the recognition site is termed as Agretope.
  • Epitopes and paratope determined the specificity of immunological reaction.
  • Epitopes are also called antigenic determinants.
  • Most epitopes haveĀ 6 to10 amino acids (T cell epitopes) or 10-15 amino acids (B-cell epitopes )
Last modified: Friday, 23 September 2011, 10:28 AM