The applicability of monoclonal antibodies (mAbs) in therapeutic research continues to rise — they now account for almost 50% of protein-based drugs. Monitoring their quality as well as binding properties are critical as these parameters provide insight into mAb functionality and efficacy as potential drugs.
Here we study trastuzumab, also known as the commercial drug Herceptin®, a monoclonal antibody that has been used to successfully treat patients with certain forms of breast cancer. Trastuzumab acts by binding to and interfering with the HER2/neu receptor in cancer patients. Using two complementary technologies, we examine how targeted oxidation affects trastuzumab structure and therefore its binding capabilities to protein A. First, a rapid analysis of the mAb preparation quality was performed using the Tycho™ NT.6 system. The same samples were then run on the Monolith® NT.115Pico system to analyze how oxidation compromises mAb interactions. Stability directly translated into binding affinity, showcasing that the Tycho NT.6 affords researchers a fast and accurate characterization of trastuzumab sample quality.