Competition between hydrogen bonding and protein aggregation in neuronal-like cells under exposure to 50 Hz magnetic field

PURPOSE: To investigate the role of hydrogen bonding and protein unfolding in human SH-SY5Y neuronal-like cells under exposure to a 50 Hz magnetic field (MF) at the intensity of 1 mT. MATERIALS AND METHODS: Neuronal-like cells were placed into an incubator in a 5% CO2/95% air humidified at the temperature of 37.1 °C and exposed for 4 h to a 50 Hz MF at 1 mT. The exposure system consisted of two Helmholtz coils driven by AC voltage at 50 Hz. Exposed and control samples were studied using Fourier Transform Infrared (FTIR) Spectroscopy. RESULTS: The vibration bands of the methylene group increased significantly after 4 h of exposure. A significant shift to low energies of the Amide I band and an increase in the intensity of the parallel and antiparallel β-sheet structures with respect to the α-helix component were observed after exposure. The Amide II frequency did not change significantly whereas a relative increase of its integrated area with respect to Amide I mode occurred after exposure. CONCLUSIONS: These results can be explained assuming that both the mechanisms of protein aggregation as well as the increase in hydrogen bonding occurred in neuronal-like cells under exposure to a 50 Hz MF.