324 IMMUNO-CATALYSIS 



per cent of the mass of the red blood cells, the weight-to-weight ratio 

 will be 1 : 5,328 (dry basis). This, of course, does not take into consid- 

 eration the fact that the hemolysin used is only partially purified. 

 This relationship becomes easily understandable when the activity 

 of hemolysin is considered as one of catalysis. This interpretation 

 appears to be corroborated by the studies of Herbert and Todd (1941) 

 which will be discussed below. 



b. A Study of the Antipneumolysin Titer of the Sera of Pneu- 

 monia Patients. In a comprehensive study on pneumolysin, Oker-Blom 

 (1948) reported the following findings. Sera of rabbits immunized 

 with streptolysin showed pronounced increase of antistreptolysin 

 values, but increased pneumolysin values could not be demonstrated 

 in the same sera when titrated with pneumolysin. Normal human 

 sera showed approximately the same antipneumolysin titer with pneu- 

 molysin from type 2 as from type 3 pneumococci. Sera of pneumonia 

 patients showed twice as high titers as normal sera. The maximum in- 

 crease of the antipneumolysin titer reaches a peak on the 18th to 23rd 

 day from the onset of the disease, followed by a decline. A systematic 

 study showed that there is a relation between an increased cold- 

 agglutinin titer and increased antipneumolysin titer. There was, how- 

 ever, no constant relation between the periods of increased antipneu- 

 molysin and increased cold-agglutination titer (for earlier findings 

 see White, 1938). 



5. Streptococcal Hemolysin 



Smythe and Harris (1940) found that Streptococcus hemolyticus 

 Strains: 1685 M, Type I (Griffith); 1048 M, Type VI (Griffith); 

 C203, Type I (Griffith). N.Y. 5, Wadsworth; B3S; and 1685 G (not 

 fatal to mice) produced the same hemolysin. The hemolysin was in- 

 activated by proteolytic digestion with trypsin, pepsin and papain. 

 Boiling destroyed it immediately, and a temperature of 56° irreversibly 

 inactivated it within a few minutes. It was completely precipitable with 

 saturated ammonium sulfate and partially with three volumes of alco- 

 hol, acetone or dioxane from the broth culture filtrates. The active 

 substance was readily soluble in glycerol. The cupric salt precipitates 

 of hemolysin were reactivated with sodium pyrophosphate. Alum 

 also precipitated the active fraction in a recoverable manner. It was 



