THE PRIMARY AND SECONDARY COMPOUNDS OF CATALASE AND METHYL OR ETdYL HYDROGEN PEROXIDE

In this and following papers, the properties of two new catalytically active enzyme-substrate compounds of catalase are given. Paper I gives spectroscopic data, Paper II and III, data on kinetics and activity, and, in Paper IV, the reactions of these enzyme-substrate compounds with hydrogen peroxide are discussed. The red catalase ethyl hydrogen peroxide compound studied by Stern (1) is characterized by two sharp bands in the green region of the spectrum and requires about 0.3 M ethyl hydrogen peroxide for maximum spectroscopic effects. Stern’s compound is, however, a secondary product of the reaction of enzyme and substrate. The primary reaction product is a green compound which has a single diffuse band in the red region of the spectrum and requires only a very small excess of ethyl hydrogen peroxide for maximum spectroscopic effects (“5 X 10” M). Catalase is here shown to form completely analogous primary and secondary compounds with methyl hydrogen peroxide (2). These primary (I) and secondary (II) compounds resemble the green and red peroxidase hydrogen peroxide compounds (see Theorell (3)). The spectra of the primary compounds of catalase with these alkyl hydrogen peroxides are related to that of the catalase-hydrogen peroxide complex (4) and give an indication of the spectrum of the latter compound in regions for which data have not yet been obtained. Preparations-Bonnichsen’s (5) catalase preparations were used in these experiments, and many thanks are due him. Ethyl hydrogen peroxide’ was prepared and standardized as described by Stern (1). According to his tests, a pure material gave the same results, and since the concentrations employed here are about 0.001 to 0.0001 of those he employed, the effect of an impurity would be smaller. Methyl hydrogen peroxide was prepared as described by Reiche and Hitz (6). The distillate was about