Glucose Isomerase Polymorphs Obtained Using an Ad Hoc Protein Crystallization Temperature Device and a Growth Cell Applying an Electric Field

In this work, we investigated the effects of the temperature on the crystal growth of a model protein: glucose isomerase. The use and design of two temperature devices on the crystallization process of the protein glucose isomerase allowed us to obtain different polymorphs. Additionally, in order to obtain insights into the concomitant crystallization of different polymorphs of this, enzyme, the solubility diagram of the protein was obtained. After fixing the maximum solubility at the optimal temperature, we tested how to separate nucleation and Crystal growth by using an ad hoc crystal growth cell applying a direct current. We succeeded in controlling the nucleation first and later the growth process moved forward by vapor diffusion. Finally, the three-dimensional structures of glucose isomerase obtained at different temperatures were assessed by X-ray diffraction, and crystallographic methods.