Control of Gibbs free energy relationship between hen egg white lysozyme polymorphs under application of an external alternating current electric field

The distribution of phases between bulk (tetragonal structure) and spherulitic crystals for hen egg white lysozyme was controlled under application of an external alternating current electric field. The distribution of phases differed depending on differences in the magnitude of the electrostatic energy contribution to the respective chemical potentials of the two solid phases. Therefore, the Gibbs free energy relationship between the two solid phases could be controlled by changing the frequency of the applied external electric field. Such a method of controlling the Gibbs free energy relationship among polymorphs would be adaptable to many kinds of protein.