348 



ENZYMES 



on the eggs of Fimduhis heteroclitus and McGuigan * with 

 diastase. 



With regard to salts, Caldwell found that nitrates inhibit 

 the action of the enzyme in somewhat greater dilution than 

 the corresponding sulphates and chlorides. He agrees with 

 Matthews that the affinity of the atom or ion for its electrical 

 charge is the main factor which determines its physiological 

 action. 



It is to be remembered that the effect of poisons vary with 

 the purity of the preparations used ; a slight admixture of pro- 

 teins and other impurities makes it necessary to increase the 

 concentration of the poison greatly in order to inhibit the 

 enzyme action. 



ANTI-ENZYMES. 



The term anti-enzyme is applied to a class of substances 

 occurring in the living organism or produced in it by sub- 

 cutaneous injection with an enzyme. The anti-enzymes are 

 antagonistic in their action upon the enzymes, and their action 

 is quite specific, the relationship between an enzyme and its 

 anti-body being similar to that existing between a toxin and 

 an anti-toxin. The first example of immunity against an 

 enzyme was recorded by Hildebrandt,f the enzyme being 

 emulsin. 



* McGuigan: id., 1904, 10, 444. 



t Hildebrandt : " Virch. Arch.," 1893, 131, 12, 26, 



