Influence of weak static and 50 Hz magnetic fields on the redox activity of cytochrome-C oxidase.

The effects of static and 50 Hz magnetic fields on cytochrome-C oxidase activity were investigated in vitro by strictly controlled, simultaneous polarographic measurements of the enzyme's high- and low-affinity redox reaction. Cytochrome-C oxidase was isolated from beef heart. Control experiments were carried out in the ambient geomagnetic and 50 Hz magnetic fields at respective flux densities of 45 and 1.8 microT. The experimentally applied fields, static and time-varying, were generated by Helmholtz coils at flux densities between 50 microT and 100 mT. Exposures were timed to act either on the combined enzyme-substrate interchange or directly on the enzyme's electron and proton translocations. Significant changes as high as 90% of the overall cytochrome-C oxidase activity resulted during exposure (1) to a static magnetic field at 300 microT or 10 mT in the high-affinity range, and (2) to a 50 Hz magnetic field at 10 or 50 mT in the low-affinity range. No changes were observed at other flux densities. After exposure to a change-inducing, static or time-varying field, normal activity returned.