This book provides comprehensive up-to-date information on the structure and function of immunoglobulins. It describes the basic features of these molecules, which assists the reader in understanding how they function as an integral part of the immune system. THE IMMUNOGLOBULINS describes the localization and structure of different binding sites of immunoglobulin molecules, including the antigen-binding site, on the basis of latest x-ray crystallography studies. It discusses recently developed biotechnological methods that allow scientists to obtain fully active antibody molecules _in vitro_ even without immunization and to construct new variants of immunoglobulins and their fragments by fusing with various other active molecules. A survey of recent knowledge on immunoglobulin-binding molecules other than antigens and on flexibility of immunoglobulin molecules concludes the discussion of functional aspects of the problem. Key Features * Describes recent reviews on the structure and function of immunoglobulin molecules of various species * Summarizes in detail recent findings on the fine structure of the antigen-combining site * Presents comparative data on the antigen-recognizing sites of other molecules such as MHC proteins and T-cell receptors * Summarizes growing data on immunoglobulin binding sites responsible for the reaction of immunoglobulins with molecules other than antigens * Explores the rapid advance of recent biotechnological methods used for the construction of antibody molecules and their fragments with new properties * Presents extensive references and is lavishly illustrated