Kinetics of the Bioluminescent Reaction in Cypridina. I

Until the present time it has been proven impossible to isolate as pure chemical individuals any of the reactants concerned in the production of light by organisms. The work of Dubois 1 and Harvey has, however, indicated the general nature of such reactions as consisting in the oxidation of a substrate, luciferin, catalyzed by an enzyme, luciferase. Harvey~ believes that luciferin should be placed among the natural proteoses on the borderland between the proteoses and peptones, whereas luciferase is a protein probably belonging to the albumin group. Quantitative studies upon such reactions are beset with several difficulties, among the most important of which are (1) absolute lack of information as to the concentration of the reactants present in extracts, and (2) the rather highly labile character of the substrate, luciferin, which readily oxidizes spontaneously without light production in the absence of the enzyme. I have made an attempt, however, to discover something of the time relations involved in bioluminescent reactions, specifically to study the rate of decay of the light produced when aqueous solutions of enzyme and substrate are added together. This paper deals with a photographic method which has been developed for this study, and with the results which it indicates.