thornton@che.udel.edu

M.S. Chemical Engineering, 1993 B.S. Chemical Engineering, 1992       Massachusetts Institute of Technology

The effect of surfactant on protein crystallization

Co-Advisor: Prof. Abraham Lenhoff

Knowledge of the structure of a protein can provide information about its function, which can aid in protein production, rational drug design and the understanding of biochemical pathways. One of the most widely used methods for determining protein structure is to perform X-ray diffraction on a protein crystal. With recent developments in diffraction technology, crystallization of the protein of interest has become the bottleneck in the process of structure determination. Although proteins have been crystallized for decades, little is understood about the fundamental forces governing this process. Generally, crystallization conditions are chosen by trial-and-error rather than through rational process design. Many soluble proteins, however, remain uncrystallized. Our research group has been working to provide a more fundamental understanding of the crystallization process that would allow a more rational approach in the design of crystallization experiments. 

In an attempt to induce crystallization, many different precipitants, including salts, alcohols, polyethylene glycol and surfactants, are added to the protein solutions. It is the goal of this research to try to elucidate the fundamental forces that govern the effects of surfactants on protein crystallization. My experimental work will focus on the use of static and dynamic light scattering to explore molecular interactions and to follow the kinetics of the initial crystallization process. These measurements will then be related to crystallization behavior. By using colloidal theory to model the intermolecular forces in protein solutions, I hope to examine how surfactant can change the protein-protein interactions and thus relate the observed experimental behavior to molecular conditions.