Abstract

The in vitro effects of extremely low frequency (ELF)-electromagnetic field (EMF) (frequencies of 50, 100, 217 Hz, induction 300 µT) on the structure and activity of acetylcholinesterase (AChE) was investigated. AChE activity was measured with UV-vis spectroscopy. Circular dichroism spectroscopy and fluorescence spectroscopy were used for investigating the secondary and tertiary structure of enzyme. The results demonstrated that the ELF-EMF decreased enzyme activity and the main inactivation took place in 217 Hz (p<0.05). It can be concluded that increasing the frequencies of ELF-EMF caused an increase in the helicity of AChE; therefore, under ELF-EMF, the α-helix structure can induce the secondary structure of AChE. Also, the intrinsic fluorescence decreased by increasing the frequency of field. 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.

Key words: Acetylcholinestrase, circular dichroism spectroscopy, extremely low frequency electromagnetic field, fluorescence spectroscopy, UV-visible spectroscopy.