334 



IMMUNOLOGY 



y\ 



H H O 



I I I! 



N 

 H 



-C— C— C— OH + I„ = I- 



I I 

 H NH, 



H H O 



I I II 

 -C— C— C— OH + HI 



I I 

 H NH. 



N 



I 

 H 



AcETYLATED Proteins. — The acetylated proteins have been ex- 

 tensively studied by Landsteiner. In such compounds the acetyl 

 group doubtless combines witli the liydroxyl (-0H) or amino 

 (-NH2) groups of the protein molecule. Thus any amino acid 

 might be acetylated in the following manner : 



H H 



I I 

 R— C— N- 



I 

 HO— 0=0 



O H H O 



H'TcTi— C— CH, = R— C— N— 0— OH, ^■ HOI 



I 



HO— C=:0 



In the case of tyi'osino the acetyl group might l)c attached to 

 either the liydroxyl (-Oil) or amino (-NIL,) group, or porliaps 

 to both. The hydroxvl linkase is ilhistrated as follows: 



H NH, 



In the case of tryptophane the reaction would be the replace- 

 ment of either the single hydrogen on the nitrogen of the indol 

 ring, or of the hydrogen in the amino (-NH,) group on the side 

 chain. 



H H O 



/\ 



N 



-C— C— C— OH 



I I 

 H NH, 



O 



i H + CI i— C— CH, 



