NONLINEAR OSCILLATORY REACTION OF CATALASE INDUCED BY GRADUAL ENTRY OF SUBSTRATE

Characteristic oscillatory reactions were observed when hydrogen perox ide migrated through semipermeable membrane into a solution of catalas e. Measurements were made with DO and an mV meter. Oscillation cleraly occurred in the range between 25 degrees C and 37 degrees C and betwe en pH 6.0 and pH 7.6. It was also shown that a driving force for the p ermeation of H2O2, which was the cause of the oscillations, was a devi ation from its equilibrium concentration. We made simulations for osci llatory reactions on the basis of these findings. The result indicated that considering the evaporation of O-2 was necessary in order to int erpret the oscillatory reactions of catalase in addition to the slow e ntry of substrate caused by deviation from the equilibrium concentrati on. The fact that oscillations arise by using this method may provide an important insight into the study of enzyme reactions mediated by me mbranes in living systems, because many enzyme reactions take place wi th the mediation of a biomembrane.