ELF-EMF exposure decreases the peroxidase catalytic efficiency in vitro

Abstract

AbstractThe activity of purified Fe3+ containing horseradish peroxidase (HRP) was recorded while the enzyme was exposed to two low frequency pulsed electromagnetic fields (ELF-EMFs) with different frequencies: 50 Hz/2.7 mT and 100 Hz/5.5 mT. No statistically significant difference in the Michaelis constant (Km) values between the control enzyme and the enzyme exposed to any of the two ELF-EMF used could be detected (53 ± 11 μM vs 67 ± 10 μM vs 42 ± 11 μM respectively), indicating that upon short exposure times, there are no large structural alterations of the enzyme that affect the substrate affinity. A 50 Hz/2.7 mT EMF did however, cause a significant decrease in the maximum rate (Vmax) value (from 3.31 ± 0.17 μmoles/min to 1.6 ± 0.19 μmoles/min, p<0.03) and a drop of the catalytic efficiency to less than half (from 0.66 ± 0.03 s-1 to 0.32 ± 0.04 s-1, p<0.05). These observations are the first experimental proofs that support the previously postulated mechanism of coupling between ELF-EMF and living systems based on a resonant frequency specific for a given ion molecule.