Survey of Reactions in Nicotinic Acid and Its Derivatives

Nicotinic acid derivatives thus occur in all microorganisms examined, in similar quantities and in the organisms studied they participate in similar processes of hydrogen transport. Equally widespread are reactions of the millimicromolar order which result in their formation, interconversion, or inactivation (Table I). The much more rapid reaction by bacillus N.C., which derives its main material and energy from nicotinic acid, emphasizes the similarity between the rates of the other reactions. 

Reactivation of cozymase by apozymase i s not spontaneous it and the reciprocal conversion of coenzymes I and II require concomitant reactions (Table II) of which, in common with reactions associated with cozymase inactivation, the main feature appears to be phosphate transfer. This does not necessarily support suggestions that the product of inactivation of cozymase may be a dephosphorylated derivative conversion of glutamine to glutamic acid and NHs by streptococci is similarly conditioned (69,71). 

Another concept of the inactivation of nicotinamide derivatives which requires cautious application is the suggestion of Lwoff and Lwoff (61) and Morel (81,82) that inactivation is a process of attrition, necessarily associated with the functioning of the substances as coenzymes, and that it is a faulty type of reaction taking place as an accident on a few out of the many 

Comparison between Rates of Reactions of Nicotinic Acid Derivatives AND Those of Associated Metabolic Processes  

Organism or preparation (reierence) (a) Reaction with nicotinic acid derivative ( i) Associated reaction  

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