186 



BIOCHEMISTRY OF FIREFLY LUMINESCENCE 



at 214 minutes and the resulting flash was recorded. It is evident 

 that the lower oxygen tension leads to a greater flash height. The 

 flash intensity is a maximum when the oxygen tension has been held 

 at approximately 0.001% or less. 



Analysis of Pyrophosphate Action 



As indicated in previous sections inorganic pyrophosphatase has a 

 profound influence on the rate of light intensity decrease after the 



12 3 4 5 6 7 



Tl ME - MINUTES 

 Fig. 19. The effect of inhibitors on the huninescent response to pyrophosphate 

 (McEIroy et al, 1953). The pyrophosphate and inhibitors were added at 

 2 minutes. 



reaction is initiated with ATP. Likewise pyrophosphatase greatly 

 affects the response of the light reaction to the secondary addition 

 of inorganic pyrophosphate and triphosphate. 



The results in Fig. 19 illustrate one type of response which can be 

 obtained by the secondary addition of pyrophosphate to a partially 

 purified luciferase system which contains pyrophosphatase. Upon addi- 

 tion of pyrophosphate (final cone. 10~* M), there is at first an imme- 



