262 



INACTIVATION OF TRYPSIN. Ill 



Methods. 



The methods used in the present experiments were the same as 

 those described above. The amount of active trypsin present was 

 determined by measuring the time required for 1 cc. of the solution 

 to cause a small amount of hydrolysis of a gelatin solution at 3>3° and 

 a pH of 6.2 (in one experiment the pH was 10). The hydrolysis was 

 followed either by the formol titration or the change in conductivity. 



Influence of the containing vessels. — Since the formula for a mono- 

 molecular reaction is the same as that for diffusion it is necessary to 

 know whether the enzyme is really being destroyed or simply diffus- 



TABLE I. 



Influence of Containing Vessel on Decomposition. 



10 cc. dialyzed trypsin placed in vessel noted, and left at 20°C., pH 6.2. 

 trypsin determined in 1 cc. after interval noted. 



ing to the walls of the containing vessel. In the latter case the rate 

 of disappearance of the enzyme will depend on the size and character 

 of the containing vessel, while if the process is chemical it will probably 

 be independent of these factors. In order to test this point trypsin 

 solutions (prepared as described in the preceding paper) were placed 

 in various vessels and kept at 22° for 17 hours. The activity of the 

 solution was tested before and after this interval. The results of 

 this experiment are shown in Table I. It is evident that the destruc- 

 tion of the enzyme is independent of the container and is therefore 

 probably not a diffusion process. The same conclusion is indicated 

 by the temperature coefficient. 



