A common theme for the effect of electric field on the
structure
and conformation of proteins is lacking due to a myriad of conflicting
reports emerging from different protein systems subjected to different
frequencies and strengths of the field (0.8 −108 V cm–1), which may be pulsed for a few nano- to
microseconds or applied continuously up to several hours. It is however
necessary to find a common theme because of the increasing use of
electric field not only to understand Stark-like electro-optic effects
in large molecules but also in food processing technology, and perhaps
in the disruption of amyloid bodies in Alzheimer’s condition.
This study finds an optimized condition of 1.3 V cm–1 DC field, in which the electrophoretic mobility is ∼1.2 mm
h–1, and systematically shows electrophoretic, electrochemical,
and unfolding effects at different levels of cytochrome c structure
within ∼90 min of turning the field on. Interestingly, the
protein undergoes amorphous aggregation concomitant with a high degree
of denaturation. In support of this suggestion, data for myoglobin
and trypsin are also presented. Effort has been made to separate out
the chemical and physical effects of the electric field.