Interloping frontiers of systems biology: Mass spectrometry in bioprocesses


Intracellular proteolysis in mammalian cells is a native cellular strategy to recycle proteins and peptides.<lb>Whether or not this mechanism may hamper monoclonal antibody (mAb) formation in CHO was the<lb>key driver for this study. Exponentially growing, anti-IL8 producing CHO cells were fed with C-<lb>labeled L-lysine. The fate of the labeling signal was tracked in intracellular peptides which were the<lb>proteolytic fragments of the mAb. Signal analysis was performed in samples after cell disruption, anion<lb>exchange solid phase extraction (SPE) and Q-ToF mass detection. Four degradation peptides were<lb>found, with HYTQKSLSLSPGK and HYTQKSLSLSPG containing two and one L-lysine unit (K)<lb>respectively. Labeling dynamics were used for model-based identification of the degradation rate in<lb>four biological replicates. Degradation rates of 1.23 to 1.89 pmol/10cells/h were estimated<lb>representing about 0.18 % of the net mAb production. Hence intracellular mAb degradation occurs<lb>even under the rather smooth production conditions installed. ________________________________________________________________________________ 117<lb>

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@inproceedings{Kopper2017InterlopingFO, title={Interloping frontiers of systems biology: Mass spectrometry in bioprocesses}, author={Andr{\'e}s S{\'a}nchez Kopper and Ralf Takors and Bernhard Hauer and Steffen Rupp and Attila Teleki and Jurek Failmezger and Annette Michalowski}, year={2017} }