In this study, the thermosensor protein GrpE was used. GrpE is the adenosine diphosphate/adenosine triphosphate exchange factor of the Hsp70 chaperone system of Escherichia coli.
Ten protein solutions were analyzed in two different solvents with different protocols, varying in the applied electromagnetic field (sinusoidal with a frequency of 0.1, 1.0, and 1,9 GHz or GSM signal), exposure time, cycle conditions (on/off duration), temperature, and electric field strength. Possible immediate (less than 0.1 second) and delayed effects (more than 30 seconds) were recorded.
|Exposure 1: 0.1 GHz|
|Exposure 2: 1 GHz|
|Exposure 3: 1.9 GHz|
|Exposure 4: 0.9 GHz||
|Setup||exposure chamber installed within the measurement compartment of a spectropolarimeter|
|electric field strength||0.3 kV/m||-||calculated||-||-|
No significant changes on the protein conformation were observed in any of the used exposure condition.
The data indicate that exposure to radiofrequency electromagnetic fields in the tested frequency range and electric field strength do not induce conformational changes in the isolated GrpE-protein.