Cascadia Proteomics Symposium

^{Date and Time: Thursday, July 17, 15:35 PT}

^{Presenter: Theresa Gozzo, Scientist I, Mass Spectrometry}

Disulfide bonds are critical in stabilizing the three-dimensional structures of antibody-based therapeutics. Free and improperly paired cysteines can lead to aggregation or immunogenicity. Other cysteine modifications, like glutathionylation, cysteinylation, or trisulfide and thioether bond formation can be considered product-related impurities, so it is essential to accurately characterize cysteines in biopharmaceuticals. Often, a bottom-up mass spectrometry approach is taken to localize disulfides and cysteine modifications; however, conditions like alkaline pH and high temperatures can lead to method-induced disulfide artifacts that complicate these analyses. Various methods have been proposed to minimize artifacts, but they only focus on the analysis of a subset of cysteine modifications, most often native and scrambled disulfide bonds. We present a method to provide a more comprehensive analysis.

^{Date and Time: Friday, July 18, 11:30 PT}

^{Presenter: Jianji Chen, Scientist II, Mass Spectrometry}

The multi-attribute method (MAM) is increasingly employed in the biopharmaceutical industry for comprehensive characterization of therapeutic antibodies. Despite advancements in mass spectrometry instrumentation, systematic comparisons of performance across platforms remain scarce . This study evaluates two widely utilized instruments, Q Exactive™ and Exploris™ 240, focusing on their capability to identify and quantify post-translational modifications (PTMs) under a design of experiments (DOE) framework. Our findings address a critical gap in MAM workflows, particularly in understanding instrument-specific performance differences in cross-site or cross-instrument data comparisons