by Yuling Zhang, PhD, Andrew Goetze, Julia M. Boyce, Mary Gerhart, Shawn Novick, Claudia Jochheim, Wayne Gombotz, and Xiaochun Qin
Volume 2, Issue 6 (November/December 2003)
Cation exchange chromatography (CEX) is a versatile method for separation of proteins based on exploiting differences in positive electrostatic charges. In CEX, proteins are bound to the negatively charged stationary phase (cation exchangers) and then eluted using a salt gradient. Typically, the liquid-phase pH in CEX is lower than the isoelectric points (pI) of the proteins. CEX has been used to monitor various post-translational modifications such as glycosylation, deamidation, phosphorylation, truncation, oxidation, C-terminal and N-terminal clipping, and N-terminal cyclization. Some of these variants may exhibit different bioactivity. Therefore, it is important to characterize protein variants and monitor the stability of these variants throughout the process of drug discovery, development, and manufacture. Characterization of complex proteins such as antibodies, has traditionally been performed using slab gel-based techniques such as isoelectric focusing (IEF). This technique is qualitative and time consuming. It also generates large quantities of chemical waste from the staining process…
Citation:
Zhang Y, Goetze A, Boyce JM, Gerhart M, Novick S, Jochheim C, Gombotz W, Qin X. Separation and Characterization of a Monoclonal IgG2 Antibody by Cation Exchange Chromatography. BioProcess J, 2003; 2(6): 37-43.