ANTI-ENZYME IMMUNITY 221 



maltose was dissolved in ferric-sulfate-sulfuric acid solution and the 

 resulting ferrous ion titrated by standard permanganate solution. 



The calculation of the enzyme activity w^as based on reaction 

 kinetics according to the equation characteristic of a reaction of the 

 first order : 



1 a 



K=— In 



t a— X 



t=time in minutes; a=the concentration of starch at the start of 

 the reaction; a—x=ihe concentration of starch after t minutes. 



The observations of numerous investigators have repeatedly shown 

 that after 70 to 80 per cent hydrolysis of the starch the reaction comes 

 to an end, and from that point on the rate of hydrolysis is negligible. 



The Immunization of Rahhits with Amylase. The rabbits used for 

 immunization weighed 2.7 and 3.9 kg. As in immunizations with 

 toxins, at the beginning 1 mg. amylase was given, subsequent injec- 

 tions being gradually increased up to 40 mg. per dose. Saline solutions 

 of amylase were saturated with toluol to maintain aseptic conditions. 

 None of the rabbits showed pathological symptoms. The injections 

 were repeated every four to six, or every four to seven days. The period 

 of active immunization was three to eight weeks, during which period 

 a total of as much as 250 mg. of amylase per rabbit was used. 



Determination of the Anti-Amylase Content of the Immune Sera. 

 The amylolytic, as well as the antiamylolytic activity of normal sera 

 were tested and found within the range of experimental error. The 

 mixture of immune serum and amylase one minute after mixing was 

 added to the starch-buffer solution. They found that the decrease of 

 amylolytic activity of such a mixture was directly proportional to the 

 volume of immune serum added. 



The inhibition of the amylase activity by the homologous immune 

 serum was independent of the formation of a precipitate in vitro. 



The extent of combination between amylase and anti-amylase was 

 found to be dependent on the duration of interaction between the two 

 reactants and on their concentrations. 



The results of the experiments in regard to the inhibition of amy- 

 lase by its homologous immune serum, expressed in the form of curves, 

 showed that increase of the concentration of immune serum propor- 

 tionally retards the speed of the reaction of the starch-amylase system. 



