Sodium Dodecyl Sulfate Removal Interface to Enable Characterization of Fragment Impurities in Monoclonal Antibodies by Capillary Electrophoresis Sodium Dodecyl Sulfate Coupled to Mass Spectrometry

PROGRAM SUMMARYMonoclonal antibodies (mAbs) have become mainstream therapeutic proteins in the biopharmaceutical industry (biopharma), and the demand for efficient analytical tools for their characterization and quality control continues to increase. During manufacturing and storage, cleavage of mAb’s primary structure can occur due to different fragmentation induced mechanisms, and the resulting fragment species can have negative implication for the safety and efficacy of the product. Therefore, fragmentation is a critical quality attribute routinely monitored to assess the purity and integrity of mAbs and mAb-derived biologics from production to commercialization.Capillary electrophoresis with sodium dodecyl sulfate (CE-SDS), which is the capillary analogue of polyacrylamide gel electrophoresis (SDS-PAGE), is widely employed for monitoring mAb fragments during production, formulation, stability, and commercial release. CE-SDS employs SDS to denature proteins and render non-covalently associated subunits separable. The separation is based on electrophoretic migration driven by the surface charge induced by SDS binding, which is proportional to the protein’s molecular weight. In a sieving gel matrix, a size-based separation is achieved since all SDS- protein complexes have similar charge-to-size ratio. CE-SDS provides excellent resolution of fragments, but lack of mass identification through direct coupling to mass spectrometry of the resolved fragments currently creates a major gap in the biopharma.GMJ Technologies (GMJ) is requesting SBIR Phase I funding to develop a micro SDS depletion electrophoresis (SDE) interface to allow direct coupling of CE-SDS to mass spectrometry (MS). The proposed interface will use free-flow zone electrophoresis mechanism to remove SDS in-line from the CE-SDS peaks of interest prior to electrospray ionization mass spectrometry (ESI-MS). With this innovation, GMJ aims to address a critical need in the characterization and quality control of mAbs from research to commercialization. By eliminating several laborious steps, the proposed device will significantly improve the efficiency in the characterization workflow for mAbs’ fragments, improve the analysis precision and sensitivity, and provide cost-saving benefits for biopharma researchers.