154 IMMUNO-CATALYSIS 



glucosidase will not hydrolyze jS-galactoside; conversely )8-galactosidase 

 will not hydrolyze )8-glucoside. 



These facts are compared below in a tabulated form: 



Table V 



Makoside: 



(a) As test antigen (with a-glucose as terminal hexose*) reacted only in 

 a-antiserum 



(b) As enzyme substrate (with yg-glucose as terminal hexose) is hydrolyzed 

 only by a-glucosidase 



Cellobioside: 



(a) As test antigen (with /^-glucose as terminal hexose) reacted only in 

 y8-antiserum 



(b) As enzyme substrate (with /^-glucose as terminal hexose) is hydrolyzed 

 only by ^-glucosidase 



Gentiobioside: 



(a) As test antigen (with ^-glucose as terminal hexose) reacted only in 

 ^-antiserum 



(b) As enzyme substrate (with ;8-glucose as terminal hexose) is hydrolyzed 

 only by /^-glucosidase 



Lactoside: 



(a) As test antigen (with /^-galactose as terminal hexose) reacted only in 

 j3-galactoside antiserum 



(b) As enzyme substrate (with ^-galactose as terminal hexose) is hydrolyzed 

 only by ^-galactosidase 



* Strictly speaking the terminal hexoses in the above disaccharides are no longer free 

 molecules and therefore should be named hexosides. 



The nature of the factors governing the specificities of the above 

 cited artificial gluco-protein antigens can be summarized as follows: 

 The antigenic specificities are confined to: (a) the structural configu- 

 rations of hexose molecules, such as glucose and galactose, (b) the 

 a- and ^^-configurations of the glycosides, such as a- and )8-azophenol 

 glycosides, and (c) the configurations of the terminal hexosides such 

 as a-glucoside in i8-maltoside, ^S-glucoside in j8-cellobioside, and i8-genti- 

 obioside, and /3-galactoside in i8-lactoside. In this connection it is also 

 to be noted that the specificities of the action of enzymes on particular 

 substrates (compared with the above carbohydrates) is governed by the 

 above configurational differences. 



The above comparison shows that there is apparently a perfect 



