CHAPTER V 



THE CLEAVAGE OF PROTEINS WITH DILUTE 

 ALKALI IN SOLUTION IN ABSOLUTE 

 ALCOHOL 



THE researches detailed in the preceding pages seem to 

 establish the following propositions: 



1. The cellular substances of bacteria consist largely of 

 proteins that yield split products identical with those 

 obtained by the hydrolysis of vegetable and animal proteins. 



It has been shown that the bacterial cellular substances, 

 when broken up with mineral acids or alkalies, furnish 

 ammonia, mono-amino and diamino nitrogen, one or more 

 carbohydrate groups, and humin substances. It seemed 

 therefore logical to conclude that the bacterial cell consists 

 largely of proteins. 



2. The proteins of the bacterial cell contain at least 

 one group which when injected intra-abdominally, subcu- 

 taneously, or intravenously in anmials, has a markedly 

 poisonous effect. 



3. This poisonous group may be detached from the cell 

 protein by hydrolysis with either dilute acids or alkalies. 



4. The dilute alkali furnishes the better means of ex- 

 tracting the poisonous group. 



5. When the bacterial protein is broken up with alkali 

 in dilute aqueous solution, at least two groups are split 

 off and pass into solution. These are the carbohydrate 

 and the poisonous groups. Both are soluble in water and 

 in dilute alcohol, and their separation, when the cell protein 

 is disrupted by alkali in aqueous solution, is difficult and 

 unsatisfactory. 



6. Since the carbohydrate group is insoluble in absolute 

 alcohol, while the poisonous group is more readily soluble 



