284 



LIGHT AND LIFE 



lA 



Z 

 UJ 



I- 

 z 



H 

 X 



o 



ZOO- 



ISO 



100 



50 



10 



20 



30 



40 



TEMPERATURE (C) 

 Fig. 7. Effect of temperature on luminescence. 



Spectral Energy Distribution 



Although the spectral energy distribution of the light from this 

 luminescent reaction has not been determined, the luminescence is 

 visible to the 5-minute dark-adapted eye, and some visual observa- 

 tions have been made. The greenish-blue color of the light in ex- 

 tracts appears to the eye to be the same color as that emitted from 

 the intact animal. 



Inhibitor Studies 



A number of ^veil-known inhibitors of other bioluminescent sys- 

 tems, as well as classical enzyme inhibitors, were tested for their 

 inhibitory action on Renilla luminescence. Table 3 shows that potent 

 inhibitors of bacterial luminescence, such as menadione and cyto- 

 chrome c (5, 13), do not inhibit the luminescence of Renilla extracts, 

 and indicates that these compounds do not oxidize Renilla luciferin 

 as they do bacterial luciferin (FMNH2) . 



Fluoride is a partial inhibitor at high concentrations, but only 

 when ATP is added. For example, when ADP is used, fluoride does 

 not inhibit luminescence, as shown in Table 3. Similar residts were 

 obtained with AMP. In the presence of ATP, however, a 33 per 

 cent inhibition was observed. Under the same conditions, a 34 per 

 cent inhibition of ATPase activity by fluoride was observed. These 

 observations support tlic suggestion that ATP is involved indirectly 

 in this system via an ATPase reaction. 



The respiratory inhibitors cyanide and azide are noninhibitory at 



