title: Protein crystallization in stirred systems--scale-up via the maximum local energy dissipation.
abstract: Macromolecular bioproducts like therapeutic proteins have usually been crystallized with µL-scale vapor diffusion experiments for structure determination by X-ray diffraction. Little systematic know-how exists for technical-scale protein crystallization in stirred vessels. In this study, the Fab-fragment of the therapeutic antibody Canakinumab was successfully crystallized in a stirred-tank reactor on a 6 mL-scale. A four times faster onset of crystallization of the Fab-fragment was observed compared to the non-agitated 10 µL-scale. Further studies on a liter-scale with lysozyme confirmed this effect. A 10 times faster onset of crystallization was observed in this case at an optimum stirrer speed. Commonly suggested scale-up criteria (i.e., minimum stirrer speed to keep the protein crystals in suspension or constant impeller tip speed) were shown not to be successful. Therefore, the criterion of constant maximum local energy dissipation was applied for scale-up of the stirred crystallization process for the first time. The maximum local energy dissipation was estimated by measuring the drop size distribution of an oil/surfactant/water emulsion in stirred-tank reactors on a 6 mL-, 100 mL-, and 1 L-scale. A comparable crystallization behavior was achieved in all stirred-tank reactors when the maximum local energy dissipation was kept constant for scale-up. A maximum local energy dissipation of 2.2 W kg(-1) was identified to be the optimum for lysozyme crystallization at all scales under study.
authors: Institute of Biochemical Engineering, Technische Universität München, Boltzmannstr. 15, 85748 Garching, Germany.
authors: Benjamin
authors: B
authors: Smejkal
authors: Bernhard
authors: B
authors: Helk
authors: Jean-Michel
authors: JM
authors: Rondeau
authors: Sabine
authors: S
authors: Anton
authors: Angelika
authors: A
authors: Wilke
authors: Peter
authors: P
authors: Scheyerer
authors: Jacqueline
authors: J
authors: Fries
authors: Dariusch
authors: D
authors: Hekmat
authors: Dirk
authors: D
authors: Weuster-Botz
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D061067:Antibodies, Monoclonal, Humanized; D003460:Crystallization / Q000379:methods*; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D007140:Immunoglobulin Fab Fragments; C541220:canakinumab; D009113:Muramidase