Nonlinear dynamic processes in open single enzyme systems

Chemical oscillations are predicted theoretically in single enzyme systems open to substrate containing a regulatory enzyme, which shows a slow substrate activation. The time-evolution of the system is well described by two ordinary differential equations. The conditions for oscillations or overshoot phenomena of the substrate concentration were analysed by numerical simulation. The existence of damped oscillations or overshoot phenomena in a regulatory enzyme reaction, open to substrate, has been proved experimentally in the pyruvate decarboxylase reaction and in the pyruvate dehydrogenase reaction. In both cases the concentration of the substrate pyruvate shows a strongly damped oscillation in a concentration range below the Km-value.