230 PROTEIN POISONS 



substance. From edestin, therefore, by the action of 

 immune serum and complement, under the experimental 

 conditions noted, a toxic product is obtained which seems 

 to correspond with the anaphylatoxin of Friedberger." 



It seems most probable that anaphylactogens, agglu- 

 tinogens, precipitinogens, and lysinogens are identical. 

 In other words, one group in the protein molecule causes 

 the animal cells to develop a substance which under certain 

 conditions may act as an agglutinin, a precipitin, or a 

 lysin. We are inclined to the belief not yet positively 

 demonstrated that the same ferment may under varied 

 conditions act as an agglutinin, a precipitin, a lysin, or it 

 may cause a deeper cleavage in the protein molecule, 

 resulting in the liberation of the protein poison. Through 

 the researches of Friedberger, Doerr and Russ, and others, 

 it has been made quite certain that anaphylactogens and 

 precipitinogens are identical, and that these properties 

 reside in the same intramolecular group. As proteins are 

 altered by heat or digestion, their properties as anaphylac- 

 togens and precipitinogens are decreased in the same 

 ratio. The protein obtained by one- third to one-half 

 saturation of serum with ammonia sulphate is strongly 

 active both as a precipitinogen and as an anaphylactogen, 

 while that obtained by full saturation is inactive in either 

 direction. Whether this is due to 'physical or chemical 

 alteration has not been determined. 



We may condense our statements concerning anaphylac- 

 togens as follows : They are proteins which when introduced 

 parenterally into animals stimulate the body cells to elaborate 

 specific ferments for the purpose of their digestion. When 

 introduced into a sensitized animal they are digested so 

 rapidly that the split products, some of which are poisonous, 

 produce certain more or less violent and characteristic 

 symptoms which may terminate in death. All anaphylac- 

 togens are proteins, and all proteins contain a certain 

 poisonous intramolecular group. This group is physio- 

 logically the same in all proteins, hence the identity of 

 the symptoms of anaphylactic shock whatever the protein 



