Polymorphism of urate oxidase in PEG solutions
Résumé
In a previous paper, we have shown that three different crystal habits exist in the urate oxidase/PEG phase diagram (Vivares, D.; Bonnete, F. J. Phys. Chem. B 2004, 108, 6498-6507). In the present paper, we show with a temperature-controlled device that these different crystal habits correspond to two polymorphs (namely, S/N and P). Furthermore, we point out how an accurate control of the crystallization parameters and a deep understanding of the phase diagram enable us to select one or the other polymorph. Finally, in a narrow part of the phase diagram, we observe an unusual nucleation and growth of one polymorph by epitaxy.