Antibody-antigen interactions

Different antibodies adopt substantially different shapes in order to recognize their respective antigens. Local and more global structural rearrangements, in addition to sequence and size diversity of complementarity determining loops, result in antigen-binding sites that can vary considerably in size, shape and charge distribution, even though the antibody framework structure remains invariant. The structures of several free and bound Fabs show that induced-fit mechanisms best describe the antibody-antigen recognition process. This affects the prediction, engineering and design of antibody combining sites.