/•. H. JOHNSON, E. H.-C. SIE, AND Y. HAN EDA 211 



a ijukk flash. A siinilar quick flash could be caused, however, by non- 

 sjjecific cytolytic agents, such as octyl alcohol or sodium taurocholate. 

 Attempts were made to prcpaic an active lucif erase from dry powders, 

 or from freshly excised rings ground with aluminum oxide antl 

 then centrifuged in the cold at high speeds, or in other ways. Tests 

 for their activity were made by adding the residue of acetone ex- 

 tracts, methyl alcohol extracts, cooled hot water extracts, and others, 

 but no luminescence resulted that could not be accounted for in 

 terms of some remaining traces of photogenic tissue. Since the 

 luminescent system of jellyfish is one of the few examples wherein 

 light emission can take place in the complete absence of dissolved 

 oxygen (24), it seems unlikely that instability of the luciferin in 

 presence of oxygen is responsible for these negative results. 



The Three Systems Best Knoivn at Present 



At tlie present time, the three biochemically best known systems 

 are those of Cypridina, of the firefly, and of luminous bacteria. The 

 over-all reactions leading to light emission in aqueous solutions with 

 minimal components can be represented by the following schemes 

 wherein C stands for Cypridina, F for firefly, B for bacteria, L for 

 luciferin, Ase for luciferase, i?-CHO for a long chain, aliphatic 

 aldehyde, the k's for rate constants, and the cofactor symbols have 

 the usual meaning: 



Cypridina 



+ hOo -^ CL + H.O 



CLH, 



\ 



+ iO. + CAse > CL + CAse + H.O + hp 



Firefly 



FLHo + FAse + ATP + Mg++ + ^O., —U 



FL.FAse.AMP + POP + Mg++ + H.O + hu 



Bacteria 



FMNH, 



+ ^Oo -^ FMN + H2O 



+ ^O,, + fiAse + R.CHO — ^ 



FMN + BAae + products + H.O + hu 



