Frequency Dependent Non- Thermal Effects of Oscillating Electric Fields in the Microwave Region on the Properties of a Solvated Lysozyme System: A Molecular Dynamics Study

Abstract

The use of microwaves in every day’s applications raises issues regarding the non thermal biological effects of microwaves. In this work we employ molecular dynamics simulations to advance further the dielectric studies of protein solutions in the case of lysozyme, taking into consideration possible frequency dependent changes in the structural and dynamic properties of the system upon application of electric field in the microwave region. The obtained dielectric spectra are identical with those derived in our previous work using the Fröhlich-Kirkwood approach in the framework of the linear response theory. Noticeable structural changes in the protein have been observed only at frequencies near its absorption maximum. Concerning Cα position fluctuations, different frequencies affected different regions of the protein sequence. Furthermore, the influence of the field on the kinetics of protein-water as well as on the water-water hydrogen bonds in the first hydration shell has been studied; an extension of the Luzar-Chandler kinetic model was deemed necessary for a better fit of the applied field results and for the estimation of more accurate hydrogen bond lifetime values.

Classical molecular dynamics simulation of microwave heating of liquids: The case of water

“…The second set of MD simulations comprised equilibrium NVT simulations to determine the static dielectric constant from the total dipole moment induced in the sample by an external static electric field 13 . In these simulations electric fields with strengths ranging from 0.0 to 0.01 V/Å, with a step of 0.001 V/Å, were applied in the x direction.…”

Investigation of Nonlinear Output-Input Microwave Power of DMSO-Ethanol Mixture by Molecular Dynamics Simulation

“…It has been suggested that understanding the non-thermal effect of microwave field with the systems under consideration is of great importance to the development of novel separation technologies 28 , 29 , selective heating, heterogeneous catalysis 30 , 31 , and in solid phase organic synthesis (SPOS) 32 – 35 . Over the past decades, a number of experiential techniques 21 , 36 – 41 and theoretical methods 42 – 45 have been carried out to illustrate the non-thermal microwave effects. Investigating the variation of dielectric property caused by external electric fields (and therefore of the microwave power) is an effective way to understand the microwave non-thermal mechanism 46 .…”

Molecular dynamics simulation of microwave heating of liquid monoethanolamine (MEA): An evaluation of existing force fields

“…Our second approach for the determination of the static dielectric constant of MEA involves equilibration of the liquid under an externally applied static electric field 20,21 . According to this method the magnitude of the total dipole moment induced by an external static electric field of intensity E is given by Equation 2.…”