Fernandez This NSF award by the Chemical and Biological Separations program supports work by Professors Erik Fernandez, Michael Shirts, and John O'Connell to analyze and predict protein structural changes during purification by chromatography. This will be accomplished by combining extensive experimental measurements, detailed molecular simulations, and thermodynamic modeling. The principal focus is hydrophobic interaction (HIC) and especially ion-exchange chromatography (IEC), vital commercial methods to separate desired proteins from chemically modified, high molecular weight, and conformational variants. The aims of the research are to 1) establish molecular details of global and local instabilities during protein adsorption to HIC and IEC media, 2) develop a methodology for predicting effects of operating conditions on structural and species distributions, and 3) test predictions with our tools for structural and chromatographic consequences of conformation changes in single- and multidomain proteins. This project will add molecular modeling tools to enable analysis of more complex, larger (?multidomain?) proteins. The outcomes should enable a priori design of surfaces and proteins to enhance selectivity and yield in both HIC and IEC for pharmaceutically relevant proteins such as antibodies.
An educational module on dynamics and equilibria of biomolecular systems will be created for use in undergraduate biochemical engineering and thermodynamics courses, including a variety of computational exercises and visualizations. Collaboration between the chemical engineers and a prominent protein-folding researcher, will enable students to work with advanced techniques on both fundamental and practical problems. Collaboration with two biotechnology companies will expose students to complex, commercially-relevant issues of protein stability and processing and provide with pharmaceutically relevant multidomain proteins. Simulation tools developed will be open-source and posted on-line for access by other researchers.