CLEAVAGE OF PROTEINS 53 



poison is more effective than the combined. 

 This belief is confirmed by the fact that the 

 free poison is easily split out of the proteoses 

 by proper chemical agents. 



The Autolytic Cleavage of Proteins. 



All proteins sooner or later undergo autoly- 

 tic cleavage. When a solution or suspension of 

 protein in water or salt solution is protected 

 from bacterial invasion by chloroform or toluol 

 and kept at about 37 the protein undergoes 

 spontaneous cleavage. SalkowsM seems to 

 have been the first to investigate this phenome- 

 non scientifically. This work has been contin- 

 ued by Biondi, Schwiening, Launoy, Jacobi, and 

 others. Most of these have given attention to 

 cellular autolysis, as this is the most interest- 

 ing phase of the subject, but all proteins, 

 whether cellular or without structure, go 

 through a similar process. Fibrin undergoes 

 autolysis quite as promptly as liver cells do. It 

 is well known that in multicellular animals pro- 

 teases are generally distributed. At first it was 

 assumed that these consist of the alimentary 

 ferments which have been absorbed and distrib- 

 uted through the body. However, research has 

 shown that the autolytic ferments differ from 

 either pepsin or trypsin. In the first place they 



