STUDIES ON BIOLUMINESCENCE. 

 IX. Chemical Nature of Cypridina Luciferin and Cypridina 



LUCIFERASE* 



By E. NEWTON HARVEY. 



{From the Department of Marine Biology, Carnegie Institution of Washington, 

 Washington, and the Physiological Laboratory, Princeton University, Princeton.) 



(Received for publication, October 12, 1918.) 

 INTRODUCTION. 



In the fourth paper of this series^ I have described the production 

 of light by the ostracod crustacean, Cypridina hilgendorfii, and some 

 of the properties of the photogenic substances found in this animal. 

 Since then I have obtained a large number of CypridincB and have 

 been able to carry out investigation along chemical lines on a far 

 larger scale. This paper deals with the characteristics of two of the 

 photogenic substances, luciferin and luciferase, in more detail. In 

 the seventh paper^ reasons are given for the adoption of Dubois' 

 terms, luciferin and luciferase, which in part correspond to my pho- 

 tophelein and photogenin, and I have described how the oxidation 

 product of luciferin, which I have called oxyluciferin, can be reduced 

 to luciferin again. The chemical change involved in the oxidation 

 of luciferin to oxyluciferin appears to be slight and comparable to the 

 change occurring when the leuco-base of a dye is oxidized to the 

 dye itself. It is therefore not surprising to find that oxyluciferin and 

 luciferin have similar properties, and, as far as I have been able to 



* Much of this work was performed in the Zoological Laboratory, Imperial 

 University, Tokyo, and I wish to acknowledge the kindness of Professors Ijima, 

 Yatsu, Watase, and Goto during my stay in the University. I am also deeply 

 indebted to Professor Ishikawa of the Agricultural College, Tokyo, for much 

 assistance in collecting material and express my sincere thanks for his interest 

 in the work. 



1 Harvey, E. N., Am. J. Physiol., 1917, xlii, 318. 



^Harvey, /. Gen. Physiol., 1918, i, 133. 



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