46 IMMUNO-CATALYSIS 



into consideration tKe occurrence of iso-antibodies as precursors or 

 prototypes of all the antibodies. 



Iso- Antibodies. From the known facts it can be concluded that 

 the unique influence of antigens apparently is the shaping of certain 

 parts or groups of normal globulins in conformity with the specific 

 parts of antigens. Even this influence does not seem to be a new 

 process of animal cells. The presence of iso-antibodies in the animal 

 systems shows that antibody synthesis is a genetically established 

 process. The formation of additional specific antibodies in response to 

 the injected bacterial and other foreign proteins appears, therefore, to 

 be an extension of the number and art of the synthesis of antibody 

 globulins already being manufactured; in other words, a change of cer- 

 tain details in the genetically determined general scheme of antibody 

 and serum globulin synthesis. 



Landsteiner (1900, 1901) described and established the occurrence 

 of iso-antibodies and their corresponding agglutinogens in human 

 blood. He divided the blood from normal individuals which he ex- 

 amined, into three groups, namely: A, B, and C, on the basis of the 

 agglutinative reactions. The sera of group A agglutinated the red 

 corpuscles of group B, but not of group C; the sera of group B 

 agglutinated the red corpuscles of A but not of group C; the sera of 

 group C agglutinated the corpuscles of both A and B. The sera of 

 the fourth group described by Decastello and Sturli (1902) failed to 

 agglutinate the corpuscles of the above cited three groups, but its 

 corpuscles were agglutinated by the sera of all of them. The blood of 

 zoologically related species shows immunological relationship; thus 

 the bloods of chimpanzee and man, mouse and rat, etc. are related. The 

 blood cells of pigeon, rabbit and man are agglutinated by goat's 

 serum; and the blood cells of each species will absorb out from goat's 

 serum its own specific agglutinin but not the agglutinin which reacts 

 with the blood cells of the other species. 



The four classical blood groups are inherited according to Mendelian 

 principles, and all experimental evidence to date points towards the 

 chromosomes as the bearers of the hereditary factors, or "genes." 

 What interests us here most directly is the fact that the synthesis of 

 these antibody globulins is a genetically determined process. 



The basic antigenic unit in natural and artificial conjugated pro- 

 teins is the natural protein itself. The prosthetic groups coupled with 



