Crystal growth of high-quality protein crystals under the application of an external electric field

Abstract

The quality of protein crystals improves under the application of an external electric field at 1 MHz. It was revealed that the improvement of the crystal quality was achieved due to the decrease in the misorientation between subgrains in the crystal, as verified by X-ray diffraction (XRD) rocking-curve measurements. Moreover, it was observed that the step free energy on the crystal surface increases under an applied field at 1 MHz, by performing in situ observations of the crystal growth. The increase in the step free energy can be attributed to the decrease in the entropy related to the shape of the step, leading to the suppression of the incorporation of impurities into the steps on the surface during crystal growth.