The inability to routinely grow single crystals of sufficient size and quality is a major roadblock to the wider application of protein crystallography. The development of more effective growth techniques requires a better understanding of the mechanism of protein crystallization. We proposed to apply some of the spectroscopic techniques used to investigate small molecule nucleation and growth to the study of the growth and nucleation of biological macromolecules Methodology will be developed using small molecule systems on which Raman studies of nucleation have been previously published. The applicability of infrared spectroscopy (GTIR-ATR) for detecting and identifying subnuclei at the very early stages of formation will also be determined. These techniques will be applied initially to amino acids, and then to peptides and proteins. Solubility data and super-saturation for proteins in H2O as a function of temperature, concentration of precipitating agent and pH will be obtained for systems studied. The use of temperature as a control parameter in protein crystal growth will also be investigated. Proteins suitable for temperature programmed growth experiments will be selected based upon either published solubility data or data obtained during the course of the proposed research.
