Part IV 



Anti-Enzyme Immunity 



A. ANALYSIS OF CERTAIN "CONTROVERSIAL" ASPECTS 

 OF ANTI-ENZYME IMMUNITY 



THE FORMATION and existence of anti-enzymes in animal systems 

 or the production of antibodies against enzymes, by parenteral 

 injection into animals of enzyme preparations, must be demonstrated 

 by the same critical tests employed in toxin-antitoxin or other antigen- 

 antibody reactions. The immune sera against enzymes must be specifi- 

 cally produced and must manifest specific serological properties or 

 must specifically inhibit the activity of the homologous enzymes in 

 vitro as well as in animals, whenever one or both of these tests are 

 experimentally possible. If such anti-enzyme sera satisfy the known 

 criteria of immune reactions, the antigenicity of enzyme proteins and, 

 therefore, the existence of enzyme antibodies can be considered as an 

 established fact. 



The experimental data concerning anti-enzyme immunity have 

 been divided into two categories to enable us to effect a reasonable 

 comparison of both the enzyme and other immune processes, and the 

 development of the various phases of the concept of "Immuno-cataly- 

 sis," in a logical order. 



We have already described in Part I of this treatise the preparation 

 of numerous immune sera against crystalline enzymes which were 

 tested by precipitation and anaphylactic reactions. The experimental 

 data to be presented in this part of the treatise deal with the results 

 obtained from experiments carried out in animals and in vitro with 

 respect to the inhibition of the activities of enzymes by the homolo- 

 gous immune sera. However, before undertaking the presentation of 

 the data certain controversial questions as to the existence of anti- 

 enzymes must be analyzed in the light of available experimental 

 facts. 



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