Chapter 6 The antigen-antibody complex: Structure and recognition

Abstract

The antigen binding site of antibodies is a chemically and structurally variable surface of amino acids located at the extremities of the arms of the -Y- shaped molecule. Six hypervariable loops (Complementarily Determining Regions) contribute to this surface and determine the specificity of the antibody. Three of these CDRs are on the VH domain and three are on the VL domain, and their relative positions in space are determined by the interactions at the VL-VH dimer interface. That interface has unusual architectural features when compared with the database of protein structures. Antibodies behave like other protein molecules when they associate with a ligand. They may change their structur..