Authors: N.J. English and D.A. Mooney
Affilation: University College Dublin, Ireland
Pages: 434 - 437
Keywords: molecular dynamics, protein, water, electromagnetic field, hydrogen bonding
Nonequilibrium molecular dynamics simulations of hen egg white lysozyme have been performed in the canonical ensemble at 298 K in the presence of external electromagnetic fields of varying intensity in the microwave to far-infrared frequency range. Significant non-thermal field effects were noted, such as marked changes in the protein's secondary structure which led to accelerated incipient local denaturation relative to zero-field conditions. This occurred primarily as a consequence of alignment of the protein's total dipole moment with the external field, although the enhanced molecular mobility and dipolar alignment of water molecules is influential on sidechain motion in solvent-exposed regions. It was found that the field-induced partial denaturation was irreversible: the protein structure did not begin to revert back towards its original structure in subsequent zero-field simulations following exposure to the e/m field.