mAb Higher Order Structure Analysis with Protein Conformational Array ELISA

The clinical and biological properties of protein-based therapeutics, or biologics, are closely related to their Higher Order Structures (HOS) which in turn can be altered by many physical and chemical conditions. A novel technology to monitor changes in monoclonal antibody (mAb) HOS is the Protein Conformational Array (PCA) ELISA which uses a bank of more than 30 antibodies to measure protein epitope change on the surface of the mAb. Using this technology, this report provided interesting findings for the first time on the HOS changes in response to the various conditions often encountered during mAb formulation development. Specifically, one IgG1 and four IgG2 native molecules in formulation buffer were compared with the same IgG which had undergone exposure to increased temperature, pH extremes and light exposure. In addition, we also examined the impact of glycation and de-glycosylation on the mAb HOS. This study demonstrated that the PCA ELISA is stability-indicating and can provide detailed HOS information that could be important for the successful development of monoclonal antibodies.