W. D. McELROY AND J. W. HASTINGS 



177 



after the addition of pyrophosphate indicates the presence of a large 

 amount of pyrophosphatase ( Fig. 10 ) . The pyrophosphatase has been 

 partially purified by means of (NH4)oS04 fractionation and a number 



TIME - MINUTES 

 Fig. 10. Effect of ATP and inorganic pyrophosphate on Hght production. ATP 

 concentration for curves A and B was 1.5 X 10'* and 1 X 10"° M respec- 

 tively. Pyrophosphate (final cone. 3 X 10 * M) was added at 3 minutes. 

 Phosphate analysis is given in the section at the right (McElroy, 1951a). 



TABLE V 



Compounds Influencing Utilization of Adenosine Triphosphate 

 in Luminescent System 



Compound 



Final concentration, 

 M X 10* 



Response- 

 % initial 



Sodium triphosphate 

 Sodium metaphosphate 

 Sodium hexametaphosphate 

 Sodium pyrophosphate 

 Thiamine pyrophosphate 

 Acetyl phosphate 

 Inosine triphosphate 

 Glycerol phosphate 

 Diphosphopyridine nucleotide 

 Muscle adenylic acid 

 He.xose diphosphate 

 Orthophosphate 



