Effects of Digestion on Antibodies 111 



Effect of Tryptic and Peptic Digestion on Antibodies, 

 especially the Precipitins. 



The resistance to tryptic digestion of the precipitin and agglutinin 

 of abrin, after the destruction of the albumen as indicated by chemical 

 reactions, has been observed by Hausmann^ an observation which had 

 previously been made upon ricin by Jacoby. Landsteiner and Calvo 

 (18, VII. 1902, p. 786) found the precipitable substance in horse 

 serum-globulin solutions to give somewhat less precipitum after tryptic 

 digestion than before. They however succeeded in obtaining a pre- 

 cipitating antiserum from rabbits treated with ox serum which had 

 previously undergone tryptic digestion, after having been coagulated. 

 According to Obermayer and Pick, this resistance to tryptic digestion 

 contraindicates the active substance being of an albuminous nature. 

 Rostoski (1902, h. p. 60) found precipitins to resist tryptic digestion, 

 and he adds that Ringer (1902) has found the globulin molecule to 

 also resist. We have referred to the opinions regarding the connection 

 between the globulins and precipitins. Michaelis and Oppenheimer 

 (1902, p. 34), on the other hand, state that blood serum is only digested 

 with difficulty by trypsin, and that large quantities of it are required 

 to exert an action, this action being exerted slowly. They find that 

 a serum reacts to precipitins as long as it remains coagulable, but 

 that it does not react when trypsin has been in contact for a sufficient 

 length of time. Serum subjected sufficiently to the action of trypsin 

 is incapable of causing the formation of precipitins in animals treated 

 with such serum. The question evidently requires further investigation. 



Destruction through peptic digestion. Leblanc (31, V. 1901, p. 361) 

 found precipitin, as also precipitable substances in sera, to be destroyed 

 by peptic digestion, as Dziergowski (1899) had previously done in the 

 case of diphtheria antitoxin. Obermayer and Pick (1902)- found the 

 precipitin-generating power of a serum destroyed by peptic digestion, 

 although large amounts of albumoses and peptones were present in 

 the treated solution. This agrees with what is stated below with 

 regard to the very doubtful properties of immunization possessed by 

 peptones. According to Jacoby {loc. cit.) peptic digestion destroys the 

 precipitable substance in egg-white, ricin, and in abrin. Michaelis 

 and Oppenheimer (1902, p. 34) also found that immunizing properties 



1 Hofmeister's Beitrthjc, ii. p. 134, cited by Landsteiner and Calvo, p. 788. 



2 See also Oppenheimer aud Michaelis (18, vii. 1902). 



