Investigation of ligand-protein binding affinity in ion exchange chromatography

BIOT 160

Ting Yang, yangt3@rpi.edu1, Wai Keen Chung, chungw@rpi.edu1, Scott A. McCallum2, James Kempf, kempfj2@rpi.edu3, and Steve M. Cramer, crames@rpi.edu1. (1) Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, (2) Director, NMR Core Facility, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, (3) Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180
A library of cationic ligands that exhibited different binding affinity to proteins at high salt conditions was studied using NMR techniques. Descriptors were calculated based on the ligand structures and Quantitative Structure Property Relationship (QSPR) models were developed. The selected features from the models were used to gain insight into the physicochemical properties of these ligands for binding proteins under high salt conditions. The NMR experiments were performed using radioisotope-labeled RNAse A and lysozyme as model proteins to investigate the effect of buffer conditions (salt concentration and mobile phase pH) on the binding behavior of these ligands to the proteins. The regions of interaction on both protein and ligand were identified and the binding kinetics was obtained. Docking calculations were also carried out to investigate the binding of these ligands. The approaches developed in this work will facilitate future design of novel mixed mode ligands for complex bioseparations.
 

Downstream Processing: Molecular Interactions and Modeling Approaches
3:00 PM-5:20 PM, Tuesday, August 21, 2007 BCEC -- 106, Oral

Division of Biochemical Technology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007