258 IMMUNO-CATALYSIS 



In experiments to determine what bacterial enzymes are inhibited 

 by antipneumococcal antisera, they found that the antisera diminished 

 in some instances almost to the point of extinction, the production of 

 amino-acids by the organism. These findings showed that the proteo- 

 lytic enzymes of pneumococcus were inhibited by the antisera. 



a. Immunity Against Proteases of Various Bacteria. In a work 

 similar to that of Dochez and Avery, Wohlfeil (1936) studied the 

 proteolytic action of anthrax bacillus, B. suhtilis, cholera vibrio, diph- 

 theria bacillus, staphylococcus and B. froteus on serum proteins. 

 As a result of their activities, the residual or non-precipitable (with 

 trichloracetic acid) nitrogen increased. His calculations showed that 

 one billion staphylococci under optimal conditions were capable of 

 hydrolyzing 3.79 g. of protein to peptones and amino acids in twenty- 

 four hours. The same number of proteus bacilli were able to hydrolyze 

 about 4.86 g. of blood serum proteins. On the basis of these observa- 

 tions, he concluded that the increase of residual nitrogen in the sera of 

 infected patients is due to the proteolytic activity of bacteria. He found 

 that immune sera inhibited bacterial autolysis. As a result of this, 

 the action of bacterial cell proteinases on serum proteins was inhibited, 

 as shown by the decrease of residual nitrogen in a system containing 

 bacteria and immune serum. The amount of residual nitrogen in the 

 presence of immune serum was considerably less than in normal serum. 

 Immune anti-enzymes against cell proteinases were present in antisera 

 against staphylococci and B. froteus. The inhibitory action of these 

 sera was specific. Immunity against the proteolytic activity of the 

 culture fluids of B. suhtilis and B. fyocyaneus was also reported by 

 Bertiau (1914). These filtrates were concentrated in vacuo at low 

 temperature and repeatedly precipitated with alcohol. The final prod- 

 ucts were dissolved in saline and filtered. The minimum active amount 

 of the enzyme solution from B. suhtilis was 0.1 ml., determined by 

 incubating with the substrate for one hour at 37°C. That of B. fyo- 

 cyaneus was 0.05 ml. Incubation longer than one hour made very little 

 difference. Bacteria grown in broth for two days yielded the maximum 

 amount of enzyme. The enzyme of B. fyocyaneus was stable at 60°C. 

 and that of suhtilis began to lose its activity even at 56°C. 



In a systematic study in which the conditions of experimentation 

 were critically controlled, Bertiau found that the activity of enzyme 

 preparations from these bacteria was inhibited by antienzyme immune 



