PROSTHETIC GROUPS, COENZYMES AND ENZYMES 



DPN 



ADH 



{2c) 



CaH.OH 



ADH 



i ADH— DPN + + G2H5OH 



{2d) 



C2H5OH 



The influence of some sodium salts of different anions on 

 the reaction velocity in the ADH-system was studied and found 

 to be unexpectedly large and interesting. Some values are sum- 

 marized in Table IV. 



TABLE IV 



Influence of Some Sodium Salts, 0.15 M, on the Reaction Velocitv, V/e 



We think very few people would have considered it likely 

 to predict in advance that, for example, 0.15 M NaBr would 

 inhibit the aldehyde-DPNH reaction by 99%. In general, the 

 table shows how careful we have to be in controlling the ionic 

 milieu when dealing with coenzyme-enzyme reactions. 0.15 M 

 chloride and 0.015 M formate were subjected to the more com- 

 plete set of analyses that allowed calculations of all the six 

 velocity constants (see Table III). 0.15 M chloride decreases 



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