Monoclonal Antiboday Disulfide Bond Shuffling Assessment by Multiple Enzyme Digest

Monoclonal antibodies (mAb) are increasing in prevalence as biotherapeutic agents. Like many therapeutic proteins, monoclonal antibodies derive their function from their structure. Disulfide bonds between cysteine residues are an important posttranslational modification which contribute to a monoclonal antibody’s secondary and tertiary structure. Guidelines from ICH (Q6B) and the FDA (April 2015) require assessment of secondary and tertiary structure, and post-translational modifications in the proposed product and the reference product. Shuffled disulfide bond arrangements represent impurities in the therapeutic and can arise from poorly optimized expression systems, processing and improper handling.