222 IMMUNO-CATALYSIS 



In experiments 10 to 17 where the reaction mixtures were not incu- 

 bated, 13.44 to 80.95 per cent of the added amylase was inhibited by 

 the addition of 0.5 to 4 ml. of immune serum. In experiments in which 

 the reaction mixtures were incubated, 30.6 to 95.7 per cent of the 

 added amylase was inhibited with 0.5 to 3 ml. of immune serum. 



Inactivated Amylase as Antigen. The enzyme was inactivated in a 

 water bath at 56 to 58 °C. for one hour. A rabbit was subcutaneously 

 injected with increasing doses of 20 to 60 mg. of inactivated amylase 

 during a period of one month and finally a single dose of 250 mg. was 

 introduced. No harmful effects were observed. The author concluded 

 that the inactivated enzyme did not produce an anti-amylase antibody. 



Specificity of Amylase-Anti-Amylase Reaction. The highly specific 

 character of anti-amylase prepared with malt amylase was demon- 

 strated by the absence of any inhibitory effect on the activity of pan- 

 creatic and salivary amylases. As the optimal activity of these two 

 a-amylases are obtained at a more alkaline pH than with yS-amylase, 

 in the tests with pancreatic amylase the H+ concentration was ad- 

 justed to 2.0X10"^, and in tests with salivary amylase a H"*" concen- 

 tration of 5.0X10"'^ was maintained with phosphate buffer. 



Specificity of Amylase in the Presence of Other Antigen-Immune 

 Serum. Precifitation System. To meet one of the objections of Bayliss 

 that the decrease of the activity of an enzyme in the presence of 

 homologous immune serum is due to the adsorption of the enzyme 

 on coexisting antigen-antibody precipitate, the following experi- 

 ment was carried out by Liiers and Albrecht. To 2.5 ml. of 0.001 

 per cent amylase solution increasing volumes of freshly obtained 

 anti-egg albumin serum were added; after treating with the ap- 

 propriate amounts of egg albumin as homologous antigen the mix- 

 ture was incubated for 15 minutes at 37°C. To this was added buffered 

 and quantitated volumes of starch solution. By varying the volumes 

 of serum and antigen they endeavored to create favorable conditions 

 to cause the adsorption of amylase on the precipitates and thereby 

 to simulate the conditions Bayliss described. In none of the numerous 

 experiments was a decrease in the activity of the added amylase in 

 the presence of egg albumin-anti-egg albumin precipitates observed. 

 In comparing their findings with those of earlier investigators, namely, 

 Schiitze and Braun (1907) and Braun and Schiitze (1909), and 

 Preti (1907) who reported the preparation of anti-amylase immune 



