Das Max-Planck-Institut Magdeburg lädt Sie herzlich zu seiner öffentlichen Kolloquiumsreihe ein. Hochrangige Wissenschaftler aus verschiedenen Fachgebieten, eingeladen vom Max-Planck-Institut Magdeburg, präsentieren ihre Forschungsarbeit.
The efficient production of proteins both for pharmaceutical but also enzyme application is of major interest in biotechnology due to its great economic importance. Mammalian cells can produce and secrete large amounts of proteins even with sophisticated post-translational modifications. Metabolism plays a key role for achieving these goals. Traditionally and even now, metabolic aspects of the optimization of production processes have mainly taken into account by media optimization and by development of feeding profiles of essential nutrients and effectors mostly using empirical methods.
A thorough metabolic network analysis allows to identify the requirements of precursors, energy and cofactors for the production and secretion. To study the in vivo metabolic fluxes related to this, methods of metabolic flux analysis relying primarily on metabolite balancing have been applied already for many years but allow only moderate resolution. The application of stable isotopes permits much higher resolution but is inherently difficult due to several facts: (i) metabolism is compartmented including chanelling, (ii) multiple substrates are taken up but also secreted in certain phases of cultivation, (iii) full steady state is achieved only in special cases, (iv) measurement of intracellular metabolites is difficult. The study of metabolic activities can be strongly supported by improved measurement of compartment-specific enzyme activities, e.g. using permeabilized cells. Permeabilized cells also allow closer studies of mitochondrial metabolism, a key point in energy supply for protein production and secretion. I will show results of our studies in this area primarily using CHO cells, the major working horse in this area.
There is, however, still a gap between the growing in-depth understanding of mammalian metabolism and its application in protein production. We are, therefore, working on methods that use methods from the metabolic engineering field and apply and adapt them to describe and model real industrial production processes. After the identification of metabolic phases, macroscopic models are developed applied to permit prediction of production processes also during scale up. Such models are then also applied to optimize e.g. feeding profiles.