Robust Analysis of Protein Charge Variants
Proteins can exhibit changes in charge heterogeneity during biopharmaceutical production and purification processes. These changes can not only impact stability, but also activity. In addition, they can cause adverse immunological reactions. The identification of charge variants in development, and their monitoring throughout manufacturing, is critical to the production of safe and effective drugs.
Proteins consist of many different amino acids comprising weak acidic and basic groups. The pH where the protein has no net charge and does not interact with a charged medium is the isoelectric point (pl). In ion exchange chromatography (IEX), the unique relationship between net surface and pH can be used for optimal protein separation. The pH defines the number of charges on the protein and also helps to stabilize the native structure of the protein in the buffer used during analysis.
Agilent has developed robust solutions for identifying and monitoring charge variants using our electrophoresis platforms, biochromatography systems, and ion exchange columns portfolio.