PROPERTIES OF ANTIBODIES

By Linus Pauling

September 26, 1941

During recent years there has been developed through the work of many investigators (Landsteiner, Heidelberger, Haurowitz, Marrack, Stuart Mudd, and others) a general idea of the nature of immunological processes. This has been extended into a detailed picture of the structure and process of formation of antibodies by the application of our present knowledge of the structure of molecules and the nature of intermolecular interactions.

My collaborators, Dr. Dan Campbell, Dr. David Pressman, and Mr. Carol Ikeda, and I have now obtained quantitative experimental results along several lines which support this picture.

We have found that bivalent and trivalent haptenes, similar to those used by Landsteiner and van der Scheer, give precipitates with antibody-antigen molecular ratio close to 1. this and other results support the postulate that antibodies effective in the precipitin reaction are bivalent.

Precipitates have also been obtained between antiserum and azoproteins with an average of only two haptenes per molecule. It has also been found that haptenes can be attached by azo groups to erythrocytes without hemolyzing the cells, and agglutination of cells has been produced with only about fifty haptenes per cell.

It was predicted that antibodies could be manufactured outside of the animal by a process of denaturing a protein and slowly renaturing it in the presence of antigen. This has now been done, with use of a variety of denaturing agents. The dye methyl blue and an azo dye containing atoxyl have been used as antigens. The protein solutions obtained have various properties characteristic of antibodies, including specificity to the antigen used and solubility of antigen-antibody precipitate in excess of antigen or of haptene.