Magnetic fields were found to have a profound effect on the dynamics of the oscillating peroxidaseoxidase (PO) reaction. Static magnetic fields up to 3000 G were applied to this biochemical reaction, and their effects on the oscillatory dynamics were investigated. When the system is in a simple periodic state, magnetic fields induce a decrease in the oscillation amplitude. When the system is in a state of complex dynamics magnetic fields may induce a shift in dynamics to a neighboring state. Thus, magnetic fields may be used for noninvasive manipulations and control of complex dynamics.

The effect of dc magnetic fields of the order of 0-4000 G on the oscillating peroxidase-oxidase (PO) reaction was studied. Specifically the effects of magnetic fields on the amplitude of simple periodic oscillations and on complex dynamic states were investigated. Magnetic fields induce a biphasic change in oscillation amplitude: At field strengths up to 1500 G, the amplitude decreases gradually by 11%. At higher field strengths the decrease in amplitude is less, and it vanishes at field strengths of 4000 G and higher. The effect of magnetic fields on complex dynamics is generally to shift the dynamics from one state to a neighboring state. Numerical simulations of a detailed model of the PO reaction support the hypothesis that the magnetosensitive step is the reduction of compound II to ferric peroxidase or the reduction of compound I to compound II or both.