Conformational changes of proteins can be resolved by DRS. In the DRS measurement, an alternating voltage is applied across a sample and the sinusoidal current as a response is obtained as a function of frequency. On the basis of the measurement result, the complex permittivity and conductance can be calculated. The complex permittivity can be related with properties determined by the charge response in a system. However, the dielectric properties at low frequency (smaller than 100 MHz) is related with the overall effective dipole moment change of molecules, because the results at low frequencies are primarily determined by the polarization of the whole protein and can indicate the overall structural change (i.e., the progress of the fibrillization). Moreover, as proteins are aggregated and form bigger oligomers or plaques, the dielectric relaxation spectroscopy and the hydrodynamical change can generate an additional characterization data of protein fibrillization.

Keywords : Dielectric Relaxation, Lysozyme, Permittivity, Hydrodynamic Radius, Dipole Moment, Aggregation, Amyloid, Folding.