620 



Dr. E. F. Armstrong. 



[Apr. 5, 



5 grammes 



Time in maltose + 5 grammes -r 5 grammes + 5 grammes 



hours. per 100 c.c. fructose. galactose. glucose. 



3 25-6 25-8 25*2 14-0 



5 34-0 34-8 28-8 18-0 



24 73-8 75-2 64-0 23'0 



Correlation of Differential Action of Enzymes with Configuration of 

 Hydrolyte. 



Combining my results with Emil Fischer's earlier observations the 

 following table is arrived at : — 



Enzyme. 



Corresponding hydrolyte. 



1 



Effect of hextose on rate of change. J 



Glucose. 



G-alactose. 



I 



Fructose. 1 



Lactase . . 



iS-Gralactosides 

 (i.e., milk sugar, /3-alkyl 

 galactosides). 



No 

 influence. 



Retards. 



No ; 



influence. j 



Emulsin . 



/3-G-lucosides 

 (i.e., most natural glucosides, 

 /3-alkyl glucosides). 



/3-G-alactosides 

 (as above). 



1 



[ Retards 

 j considerably. 



J 



Retards 

 slightly. 



I 



No ! 

 influence. \ 



\ 



Maltase . . 



o-Grlucosides 

 (i.e., maltose, a-alkyl 

 glucosides). 



a- Galactosides 

 (i.e., a-alkyl galactosides). 



1 



! Retards 

 j considerably. 



J 



Retards 

 slightly. 



i 

 i 



No ! 

 influence, i 



i 



Invertase 



Fructosides* 

 (i.e., cane-sugar, raffinose, 

 gentianose, manneotetrose). 



No 



influence. 





[Retards, j 



j 



The compounds entered in the second column of the table are those 

 which, according to Emil Fischer, are alone hydrolysed by the 

 particular enzymes indicated in the first column. My own observa- 

 tions on the specific retarding influence of the various hexoses are 

 entered in the remaining columns. It is clear that the only hexoses 

 which retard hydrolysis by any given enzyme are those derived from 



* It is probable that these compounds are not derivatives of fructose of the — OR 

 <type corresponding to the simple glucosides ; probably the linkage is of a peculiar 

 .character, two centres being concerned. In this connection, it may be mentioned 

 that invertase has no action on methyl fructoside, a substance in every way 

 .analogous to methylglucoside. This point will be more fully dealt with in a later 

 (Communication . 



