Structure of antibodies.

Vertebrates develop a highly specialized system of defense mechanisms as a result of continuous stimulation by foreign materials from the environment. Whether free in body fluids or attached to cell surfaces, antibodies play the key role in the recognition of, and protection of the body against, foreign substances. Important characteristics of anitbodies are their adaptive production as a result of antigenic stimulation and the specificity they exhibit in their reaction with the antigen that induced their production. Antibodies are present in the globulin fraction of the body fluids and are summarily called immunoglobulins. Knowledge pertaining to antibody structure has been acquired principally from research of the last two decades. During this period many important findings have been made that are applicable to other proteins; in fact, anitbodies are presently the most completely characterized of the complex proteins. This paper will encompass a brief review of the structure of antibodies. The rapid development in this field makes it difficult to ensure the inclusion of all appropriate publications, and therefore we shall refer the reader principally to the most recent review articles and books which can be examined for more detailed information. Of these, four deserve special attention: Kochwa & Kunkel (1971), Amos (1971), Merler (1970), and the Cold Spring Harbor Symposia on Quantitative Biology (1967). [ABSTRACT FROM AUTHOR]