Immunochemical mapping of hCG and hCG-related molecules

The general observations and experiences of three laboratory groups that have studied the immunochemistry of hCG are summarized. A basic model of the types of antibodies which are most frequently observed has been constructed using the information gathered. Although the immunochemical mapping of the surface of any globular protein is very complex, it was possible to segregate the immune response of mice to hCG into five distinct classes of antibodies based on their binding properties. Each of these types or classes of antibodies can be further subdivided and are obviously binding to different combinations of amino acids on the surface of the hormone. We have attempted to coordinate the nomenclature of the various investigators into a simple scheme for better understanding. The recognition of these different types of antibodies has permitted the development of sensitive and specific immunological measurement systems.