268 



EST ACTIVATION OF TRYPSIN. HI 



rium equation over a range of 2,500 per cent dilution, since the 

 values for the constants were determined in a solution which had been 

 diluted 25 times and which in addition contained gelatin, whereas 

 in the calculation the same formula was applied to a solution which 

 had not been diluted at all and which contained no gelatin. This 

 experiment appears to furnish strong confirmation of the validity 



TABLE II. 



Concentration of Inhibitor and Rate of Inactivation of Trypsin at 38°C. 



10 cc. dialyzed trypsin and noted units inhibitor placed at 38°C. 1 cc. removed 

 after intervals noted and added to 25 cc. of 2 per cent gelatin pH 6.2, specific 

 conductivity 2.2 X 10"^ at 33°C. and rate of hydrolysis followed; this gives 

 the units of free trypsin per cc. solution when diluted 1:26. K = 0.1. Kd 

 (decomposition trypsin) = 0.005. 



of the mechanism proposed for the reaction between the trypsin and 

 inhibitor. It also shows that the equilibrium is not effected to any 

 extent by the gelatin. The conclusion seems unavoidable that little 

 or no trypsin is combined with the gelatin. The fact that gelatin 

 has no protective influence on the trypsin also points to the same 

 conclusion. 



