The Significance of Latency Time in Enzyme Determination

Bredlg and von Bemeck,* in their work on inorganic ferments, determined the catalytic activity of platinum and manganese salts on hydrogen peroxide by means of titration with potassium permanganate. In many of their experiments they found, however, that the reaction velocity increased during the reaction. Bredig and Marck 2 attempt to explain this fact by a gradual activation of the catalyzer by the substrate. Denham 8 believes that the increase in reaction velocity is due to absorption at the surface layer. The results of Waentig and Steche 4 on blood catalase seem to indicate that the increase in reaction velocity is not a constant feature of the catalase; they found a constant, or even a decreasing, reaction velocity. Senter/however, obtained opposite results with the same enzyme; there were cases in which the velocity increased. I t seems to me that the controversy between different authors can, at least partially, be solved by the following considerations. As I was able to demonstrate, the reaction does not start immediately after mixing the hydrogen peroxide with the enzyme solution. For this experiment I used an autographic registration of catalase action in a manometer. A certain latency period shows itself before the reaction starts. Probably an adsorption compound is formed during this latency period, which on decomposition liberates the oxygen. In one case, I obtained a latency time of 98 seconds while