Investigation of the Effect of Sodium Selenate on Acetylcholinesterase Activity under Extremely Low Frequency Electromagnetic Field

Acetylcholinestrase (AChE EC 3.1.1.7) is one of the most important enzymes in nervous
system, which plays a role in Alzheimer’s disease. Selenium is a vital micronutrient and
many investigations have been performed about the physiological, biochemical and
behavioral effects of this element, such as postponing the Alzheimer's symptoms in the
elderly and delaying the initiation signs of skin aging. Recent studies have shown that this
element protects various enzymes against the toxicity caused by heavy metals such as; Pb, Al,
Cu and Cd. AChE activity is altered under the influence of extremely low frequency
electromagnetic field (ELF-EMF). In this study, the effects of ELF-EMF, with 0.3 mT field
intensity and 50, 100, 217 Hz frequencies, were investigated on the AChE, in the presence of
different concentrations of sodium selenate, using UV-Visible, fluorescence and circular
dichroism spectroscopic techniques. The results demonstrated that the enzyme activity
declined by increasing the frequency and the amount of sodium selenate. Also, significant
structural changes occurred in the secondary and tertiary structures of AChE. Our results
showed that with increasing the concentration of sodium selenate transition from α-helix to
β-structure was appeared in the presence of ELF-EMF. In conclusion, according to changes
observed in the secondary and tertiary structure of enzyme, it is proposed that these fields are
able to affect the structure and dynamics of the active site gorge of AChE.