Published on: Sep 29, 2013
Differences in thermal characteristics of protein ?-lactoglobulin exposed to RF electromagnetic fields
Christian Beyer1 & Jürg Fröhlich
1Laboratory for Electromagnetic Fields and Microwave Electronics, ETH Zürich, Zürich, Switzerland, 8092
My presentation at the BioEM13 was about a mechanism-oriented study addressing the potential effects of Radio Frequency ElectroMagnetic Fields (RF-EMF) on the conformational state and folding kinetics of ? – lactoglobulin, one of the most common whey proteins. A direct effect on the conformation of proteins is one of the current hypotheses about a potential interaction mechanism of EMF with biological cell cultures and microbiological solutions. Proteins are the key molecules in living organisms, carrying out most of the biological functions. Their biological activity depends on their conformational state, i.e. their native three-dimensional structure. Changes in protein conformation could therefore affect downstream biological processes, e.g. in metabolic or signalling pathways. In this study the bovine protein ?-lactoglobulin is exposed to RF-EMFs while its potential structural changes are simultaneously monitoring by circular dichroism spectrophotometry. Thus, the point of observation becomes identical with the site of the potential interaction in both space and time; a situation that is expected to allow for the detection of even small effects of RF-EMFs. No non-thermal response to RF-EMF exposure was detected on the conformational state or the folding kinetics of ?-lactoglobulin applying different experimental protocols. The experiments demonstrated the necessity of multiphysics numerical analysis to achieve controlled exposure conditions taking all possible side effects into account. It also showed the need for an initial appropriate statistical analysis regarding the required number of repetitions in order to achieve a high sensitivity to allow for reliable statements and prevent “Null” events. Future work could include an extension of this approach to nucleic acids or to membrane proteins attached to a lipid bilayer.
My research supervised by Dr. Jürg Fröhlich at ETH Zürich and in part in collaboration with Prof. P. Christen and PD I. Jelezarov from the Dept. of Biochemistry, University of Zurich, focuses on protein conformation and folding kinetics to identify sites of potential interaction for either RF-EMF induced non-thermal effects or pulsed-magnetic-field-stimulated effects leading to detectable enhancement in cell proliferation. As a secondary interest I am examining the sensing capability of EMF for continuous glucose monitoring. The fields might be detectably altered by changes in conformation of the transmembrane protein GLUT1 in erythrocytes, which are triggered by alterations in glucose concentration. All my investigations include the design of experiments, the characterisation of the experimental system derived, the measurements with the biological objects and the statistical evaluation of the results. I will graduate from my PhD programme around the date that this newsletter is published. I am currently looking for a Post-Doc position in an interdisciplinary research team which would allow me to examine how to use EMF not only for diagnostic, but also for therapeutic purpose.