234 



LIGHT AND LIFE 



> 



CO 



z 



LlI 



UJ 



o 



UJ 



CO 

 UJ 



q: 

 o 



3 



10 



30 



35 



Fig. 



15 20 25 



TIME — MIN. 

 Edcct of adenylic acid and pyiopliospiiatc on oxyhicitcryl-CoA 



decomposition. 



Other Factors Afjecting the Light Reaction 



The re,sults shown in Fig. 13 indicate that the pW optinuun for 

 the flash height in the presence of glycine or glycyl-glycine buffer is 

 approximately 7.8 (11) . In phosphate buffer the light intensity ap- 

 pears to be greatly reduced and, as Avill be discussed later, the actual 

 emission spectrum is altered. The effect of temperatme on the flash 

 height is shown in Fig. 14. The experimental energy of activation 

 for the reaction is calculated to be approximately 18 kilocalories per 

 mole. The decrease in the light intensity above the optinuun of 25°C 

 is due to the reversible inactivation of the luciferase. 



The results presented in Fig. 15 indicate that oxygen is an absolute 

 requirement for the light-emitting reaction (10). Maximum lumines- 

 cence is observed at an oxygen concentration greater than ajjproxi- 

 mately 0.5% and really significant tlecreases in the light intensities 

 are not observed initil the oxygen concentration is less than 0.1%. 

 The results presented in Fig. 16 were obtained by de-aerating the 

 enzyme solution prior to the mixing of the reactants. The reaction 



