Coherent x-ray diffractive imaging and nucleation of protein crystals

The determination of the atomic structure of proteins is very important since much understanding of biological processes cannot be achieved without knowledge of the atomic structure. The preparation of high quality protein crystals suitable for structure determination often proves difficult and even impossible. The technique of coherent x-ray diffraction was used to try to gain a better understanding of protein crystal nucleation and growth. Results are presented along with technical difficulties arising from radiation damage. The results reveal the presence of surface strain in micron-sized protein crystals. Studies of nucleation at low temperature were performed along with simulations. The analysis revealed that isotropic nucleation was the main pathway but that nucleation also proceeds in a more planar fashion in some cases.