ANTI-ENZYME IMMUNITY 319 



antilipase activity of the serum of sensitized rabbits was stable to heat- 

 ing for 30 min. at 57° but not at 80°. 



c. Hemolytic Toxin of Clostridium Septicum. Bernheimer 

 (1944a) studying the relation of the lethal toxin to the hemolysin 

 produced by Clostridium seyticum, strain 44, reported that the hemo- 

 lytic and lethal actions of crude toxin are functions of a single sub- 

 stance or that they are functions of two substances which have similar 

 physical, chemical, and antigenic properties. This conclusion was based 

 on the following observations: (1) the lethal activity of cultures is 

 directly proportional to their hemolytic activity; (2) hydrogen peroxide 

 diminishes to the same extent the hemolytic and lethal activities; (3) 

 the hemolytic principal and the lethal toxin are adsorbed to approxi- 

 mately the same extent by charcoal, and kaolin; (4) erythrocytes re- 

 move the lethal activity as well as most of the hemolytic activity from 

 the culture supernate; (5) both lethal toxin and hemolytic principle 

 are partially destroyed in dilute solution at 36°C.; and (6) the anti- 

 hemolytic capacity of antitoxic horse serum is directly proportional to 

 the antilethal capacity. On the basis of the results obtained from kinetic 

 study of the hemolytic reaction with respect to concentration, tempera- 

 ture and hydrogen ion concentration, Bernheimer (1944b) observed 

 a resemblance to enzyme-catalyzed reactions, except that there was 

 absent a clearly defined pH optimum. 



4. Pneumococcal Hemolysin 



Pneumococcal hemolysin is found in the lytic extract of pneumococci 

 that causes the death of guinea pigs on intravenous injection. It is 

 destroyed by the action of trypsin. Its activity is prevented by the 

 presence of minute amounts of cholesterol. Injected into rabbits and 

 sheep, the hemolysin produces antihemolysin, which is species specific. 

 Hewett and Famulener (1922) inferred, and Avery and Neill (1924) 

 confirmed, that the hemolysin was an intracellular product liberated 

 from the autolyzed organisms. The latter investigators made further 

 observations to the effect that the hemolytic extracts undergo auto- 

 oxidation. Neill (1926) later showed that auto-oxidized inactive hemo- 

 lysin is reducible and thereby rendered reactive by sodium hydro- 

 sulfite. 



Schwachmann, Hellerman and Cohen (1934) stated that the activ- 



