40 IMMUNO-CATALYSIS 



The immune sera of the rabbits contained from 30 to 40 antiurease 

 units per ml. and the amount of antiurease in the blood serum of an 

 immune hen varied from five to 24 neutralizing units per ml. The 

 rabbit immune serum precipitated urease in dilutions up to 600,000. 

 Urease which had been denatured by contact with 0.05 N hydrochloric 

 acid for a few seconds and which was then brought to neutrality gave 

 no precipitate with antiurease whatsoever. Urease completely inacti- 

 vated by formalin was non-toxic and produced no antiurease when 

 injected into rabbits. 



It was shown that antiurease protected animals from poisoning 

 with urease. When two rabbits were given 90 neutralization units of 

 antiurease each and three hours later 90 units of urease were given 

 there were no symptoms of poisoning. A rabbit given 90 units of anti- 

 urease just before being given an injection of 80 units of urease was 

 likewise unaffected. On the contrary, two rabbits which were given 

 injections of 90 units and one rabbit given an injection containing 80 

 units of urease all died within five hours. All injections were intraperi- 

 toneal except the third rabbit which received the antiurease by ear 

 vein. 



In order to find out whether rabbits near death from urease poison- 

 ing could be saved by injecting antiurease, six two-kilogram rabbits 

 were injected intraperitoneally with 65 to 70 units of urease. When 

 the rabbits had become totally paralyzed ( 1 V^ to two hours afterwards) 

 each rabbit was given 80 units of antiurease by injection into the ear 

 vein. Four of the rabbits showed immediate improvement and became 

 normal within one hour. The other two died. Similar results were 

 obtained with guinea pigs. 



Antibody against Trypsin, Chymotrypsin and Chymotrypsinogen. 

 The methods of preparation and chemical properties of some of the 

 crystalline enzymes as found by the Rockefeller group at Princeton 

 are compiled in a book by Northrop, et al. (1948). Since it was dem- 

 onstrated that chymotrypsin differs in its properties from trypsin. 

 Ten Broeck (1934) undertook the demonstration of an immunological 

 difference between the two enzymes. Trypsin and chymotrypsin are 

 the enzymes principally responsible for the proteinase activity of pan- 

 creatic juice. Neither alone digests protein very far, but the two to- 

 gether cause hydrolysis to proceed to the polypeptide stage. Trypsin 

 decreases the clotting time of normal or hemophilic blood, but under 



