60 



fungi and the amount of their catalase. Like the other investi- 

 gators, he found that in dilute solutions and with a relative 

 excess of the enzyme solution, the reaction followed the equation 

 for reactions of the first order, thus tending to show that active 

 oxygen was formed. In some cases he found that the physico- 

 chemical constant k' equalled 0.0107 at 15°, this value for k' being 

 identical with that found by Bredig and his collaborators for a 

 colloidal platinum solution containing 0.006 gram of the metal per 

 liter. The enzyme solution used by Euler in this determination con- 

 tained 0.004 gram of enzyme preparation per liter. This enzyme 

 was associated with globulin, but, taking the molecular weight as 

 1000, while that of platinum is 195, then 0.006/195 N equals the 

 concentration of platinum and 0.004/1000 N equals the concentra- 

 tion of enzyme. This will give one an approximate idea of the 

 tremendous catalytic activity of both of these substances. Not 

 only do colloidal metal solutions and the vegetable catalases 

 act in the same quantitative manner, but they also show the 

 same sensitiveness to chemicals. 



It seems likely that there is an antagonistic action between 

 peroxidase and catalase. Shaffer" found that if uric acid were 

 allowed to stand for several days with hydrogen peroxide solu- 

 tion, it was oxidized, but in the presence of catalase and hydrogen 

 peroxide, there was no oxidation of the uric acid. This led 

 Shaffer to believe that the spontaneous decomposition of the 

 hydrogen peroxide results in the formation of traces of active 

 oxygen, while that set free under the influence of catalase is 

 wholly in the molecular (inactive) state. The main point of 

 Shaffer's publication is that the oxygen set free by catalase is 

 not in a nascent state and therefore catalase may have a certain 

 protective power in the oxidation processes carried on by the cell. 

 Herliztka^^ agreed with Shaffer that catalase has a protective 

 action in the presence of peroxides or peroxidases. He also made 

 quantitative studies on the oxidation of guaiacum by peroxidase 

 and found a retarding action in the oxidation whenever catalase 



"Shaffer. Some Observations on the Enzyme Catalase. Am. Jour. Physiol. 

 14: 299. 1905. 



28Herliztka. Richerche sulla catalasi; SuH'antagonismo tra catalasi e peros- 

 sidasi. Rendic. Accad. Lincei. Atti. V. 16^: 493. 1906. 



