ANTIGENS AS BIOCATALYSTS 35 



2500:1. His findings show also that the ratio of mg. of antibody pro- 

 duced per mg. of antigen injected, for rabbits that have been im- 

 munized was considerably smaller than the one obtained for the 

 horse. In the five sera examined they ranged in the order of 550:1, 

 550:1, 200:1, 400:1, 1000:1, respectively. 



Pappenheimer (1940) immunized a horse against egg albumin. Dur- 

 ing the entire course of injections the horse received a total of 1 .9 g. 

 of egg albumin. Assuming that the animal contained 25 liters of serum 

 at the time of the final bleeding the total circulating anti-egg albumin 

 antibody was estimated to be in the neighborhood of 50 g. 



A horse was immunized vdth a total of 60 mg. (20,000 Lf . units) of 

 diphtheria toxoid by Dr. W. B. Rawlings of the National Drug Com- 

 pany over a period of one month. At the end of this period the horse 

 contained 2150 units of antitoxin per ml. of serum, equivalent to 25 

 mg. of antitoxin per ml. which was estimated (Pappenheimer, 1940) 

 to correspond to more than 600 g. of total circulating antitoxin or 

 more than 10,000 times the weight of antigen injected. 



d. Absence of Inorganic Catalysts, Enzymes and Antigens in the 

 Catalyzed Reaction Products. In the preceding pages several quan- 

 titative studies were cited demonstrating that the amount of a catalyst 

 or an enzyme in ratio to the amount of the products of reaction they 

 accelerate is incomparably small. Likewise, experimental data were 

 cited demonstrating that the ratio of the amount of antibody produced 

 to the amount of antigen used is strikingly disproportionate. These 

 quantitative relationships can be interpreted to signify that the antigen 

 could not have entered into stoichiometrical chemical union with 

 y-globulin to form the final antibody complex. Miiller (1917), Heidel- 

 berger and Kendall (1930), Topley (1930), Hooker and Boyd (1931) 

 have expressed this view in opposition to the Biichnerian hypothesis of 

 antibody formation. Hooker and Boyd after having calculated that one 

 molecule of active antigenic substance gives rise to an amount of 

 agglutinin capable of flocking 600 bacteria, and that the surface 

 relationship between one globulin molecule and 600 bacteria is 

 1:25,000,000, stated that "A theory of antibody formation involving 

 catalysis would seem more promising." 



If our assumption that antibody produced by catalytic acceleration 

 of antigen is true, then we must be able to demonstrate chemically 

 that antigen is actually absent in the antibody molecule. For when 



