Hydrogen bonds play an important role in the formation and stabilization of the protein secondary structure. The delicate balance between many competing bonds can be altered by external stress, changing the structure of the protein.
12 samples were exposed to the magnetic field and the same number was used as the control group.
Exposure duration: continuous for 4 hours
|Exposure duration||continuous for 4 hours|
|Chamber||20 cm2 culture flasks between coils in incubator with 5% CO2 and 95% humidified air at 37°C|
|Setup||two Helmholtz coils with pole pieces of round parallel polar faces; samples were placed at the center of a uniform field area between the coils; each coil had n=124 turns of wire and the coil spacing was assumed to be equal to the coils radius (r=150 mm); during the exposure, no significant increase in the temperature (± 0.1°C) was observed; magnetic field was perpendicular to the culture flask|
|magnetic flux density||1 mT||-||measured||-||-|
The amount of methylene groups was significantly increased in exposed cells compared to the control group. This might indicate an increase in cellular volume which would correspond to an increase in the surface area and the overall cellular content with fatty acids and phospholipids and a relative increase of methylene groups with respect to methyl groups.
Moreover, a significant decrease in primary amides and a significant increase of beta sheet structures in exposed cells compared to the control group indicated changes in the overall protein conformation state within the cell, which could be due to unfolding of proteins and formation of aggregates.
No significant changes were found for secondary amides.
The authors conclude that exposure to a 50 Hz magnetic field might increase both hydrogen bonds and protein unfolding processes in neuronal-like cells.