Leo Jakob

Lectures

• Year: 2022 -  Multimerization of a Circularly Permuted Caspase and its Imlications in Bioprocessing

  Autoren: Jakob, L; Mesurado, T; Jungbauer, A; Lingg, N

  Event: 35th International Symposium on Preparative and Process Chromatography PREP 2022

• Year: 2021 -  In HIC, mixtures of two different salts can increase dynamic binding capacities (DBC). Although this phenomenon has been known for over a decade, the underlying mechanism is not understood. We have investigated whether ionic strength or surface tension of the load solution determines DBC in dual salt systems. The dual salt systems contained sodium citrate and a second sodium salt (either acetate, phosphate or sulfate) at pH 6. The stationary phase was Toyopearl Butyl-650M. Monoclonal antibody (adalimumab), lysozyme and GFP were used as model proteins. In order to analyze the intra- and intermolecular structure of the model protein in solution, we have performed small angle X-ray scattering (SAXS) experiments in said buffers without the stationary phase. Furthermore, we have analyzed the model proteins bound to the stationary phase with SAXS. For analysis of the data, we have fitted a self-avoiding random walk model and compared the resulting parameters of the loaded resin with the bare resin. Ultimately, we could show that the ionic strength of the buffering system is more decisive than the surface tension. Nevertheless, DBCs of the systems with comparable ionic strength still vary up to 30 %. The SAXS analysis revealed comparable internal structure for all investigated systems and protein-protein interactions for lysozyme and adalimumab. Systems exhibiting protein-protein interactions show non-Langmurian adsorption behavior which highlights the importance of lateral interactions in HIC. The SAXS analysis of the protein-stationary phase showed that the excluded volume of the self-avoiding random walk model inversely correlates with dynamic binding capacities.

  Autoren: Leo Jakob, Beate Beyer, Catarina Janeiro Ferreira, Nico Lingg, Alois Jungbauer, Rupert Tscheließnig

  Event: ISPPP 2021