Antigen-antibody interactions at the molecular level: adventures in peptide synthesis

Following a binding interaction between a foreign molecule (antigen) and a receptor molecule on one or more vertebrate cell types, antibodies (immunoglobulins) are the major soluble effector molecules produced. Ideally, these bind only to the inducing antigen. Clearly, the specific and avid interaction of antigen with antibody, initially at the membrane of B lymphocytes and subsequently in circulation, is central to an effective defensive role for the antibody response. In order to provide for sufficient diversity to respond to many different foreign molecules, a number of sophisticated genetic mechanisms have evolved to maximize the pool of immunoglobulin receptors(1). Development of a procedure for the synthesis and testing of large numbers of peptides on solid supports(2) has provided new insights into the molecular basis for antibody specificity and the energetics of antigen-antibody interaction. In this article Mario Geysen summarizes observations made from the results obtained from the testing of a very large (>40 000) number of chemically synthesized peptides with a variety of monoclonal and poyclonal sera raised to diverse antigens (>10(6) individual assay values).