146 IMMUNO-CATALYSIS 



of the investigators of that early period and must have stimulated 

 research along these lines. The early literature would seem to reveal 

 the fact that these investigators experimented on the theory that the 

 antitoxins played the role of specific enzyme inhibitors. For during this 

 period, immunologists and enzyme chemists discovered numerous 

 "normal" antitoxins, hemagglutinins and hemolysins, as well as natu- 

 rally occurring enzyme inhibitors. Along with these findings, numerous 

 investigators concerned themselves with the production of antibodies 

 against known enzymes, using enzymically active preparations as 

 antigens. They are: anti-emulsin (Hildebrandt, 1893), antiserum in- 

 hibiting the liquefaction of gelatin by staphylococcus and B. 'pyo- 

 cyaneus (Von Dungem, 1899), anti-rennin (Morgenroth, 1899; Kor- 

 schun, 1902), anti-cyanurase (Morgenroth, 1900), anti-trypsin 

 (Achalme, 1901), anti-coagulin (Wendelstadt, 1901; Bordet and Gen- 

 gou, 1901), anti-inulase (Saiki, 1907), antiserum inhibiting the pro- 

 duction of pigment by fyocyaneus (Gheorghievsky, 1899), anti-hlastic 

 immunity against anthrax bacillus (Ascoli, 1908), anti-serum inhibit- 

 ing the pneumococcal enzymes (Dochez and Avery, 1916), and anti- 

 serum inhibiting the formation of methemoglobin by pneumococcus 

 (Cole, cited by Dochez and Avery, 1916). 



The above citations show that during the period of 1890-1907, along 

 with the pioneering observations on the toxin-antitoxin reactions, there 

 was considerable activity in the study of anti-enzyme immunity. Un- 

 fortunately researches in this direction slowed down to such a negligible 

 rate that until a decade ago investigations reminiscent of the activity 

 of the earlier workers are rarely encountered. There has lately come 

 about a renewed interest in anti-enzyme immunity due, probably, to 

 the isolation of known enzymes in crystalline form. The recent findings 

 with crystalline enzymes have established, beyond doubt, the antigenic- 

 ity of enzymes. In fact the antibody against urease has been shown 



and a-1-arabinoside. There is no evidence as to the presence of individual enzymes for 

 each of the above substrates. A ^-d-glucosidase is beheved to be responsible for the 

 hydrolysis of all of them (R. Weidenhagen, 1932; Helferich, 1933). 



According to Weidenhagen (1940) there are only glucosidases, the principal spec- 

 ificity of which is confined to the constitution and configuration of the glycosidic 

 sugars. The nature of the glucosidic pairs, whether sugar or aglycon, for the hydrolytic 

 process as such are unessential, and exercise only a relative degree of specificity, par- 

 ticularly on the rate of hydrolysis. For instance, the ratio of speeds of hydrolysis 

 between phenyl-^Q-d-glucoside and phenyl-jg-d-xyloside is 150 to I; that of saligenin- 

 ^-d-galactoside to methyl-/3-d-galactoside is 60 to 1. It is stated by Weidenhagen 

 that "there is no special key for each lock but a master key for a group of locks." 



