Date Published: June 1, 2018
Publisher: Springer Berlin Heidelberg
Author(s): Yanli Wang, Quan Chen, Mo Xian, Rui Nian, Fei Xu.
In recent studies, electronegative multimodal chromatography with Eshmuno HCX was demonstrated to be a highly promising recovery step for direct immunoglobulin G (IgG) capture from undiluted cell culture fluid. In this study, the binding properties of HCX to IgG at different pH/salt combinations were systematically studied, and its purification performance was significantly enhanced by lowering the washing pH and conductivity after high capacity binding of IgG under its optimal conditions. A single polishing step gave an end-product with non-histone host cell protein (nh-HCP) below 1 ppm, DNA less than 1 ppb, which aggregates less than 0.5% and an overall IgG recovery of 86.2%. The whole non-affinity chromatography based two-column-step process supports direct feed loading without buffer adjustment, thus extraordinarily boosting the overall productivity and cost-savings.
In biopharmaceuticals, the purification of recombinant immunoglobulin G monoclonal antibodies (IgG mAbs) produced in Chinese hamster ovary (CHO) cells are usually achieved by 3–4 successive chromatographic steps (Girard et al. 2015; Shukla and Thömmes 2010). Affinity chromatography of protein A is extensively used as the primary capture and regarded as the industrial standard (Ghose et al. 2005; Tarrant et al. 2012). Nevertheless, protein A chromatography has its inherent disadvantages, such as relatively low binding capacity, high material/operational cost and ligand leachability, which add another impurity into the process (Shukla et al. 2007; Tao et al. 2014).
Many platform technologies have been developed for IgG mAbs purification. Ion-exchange chromatography (IEX) as one of them was extensively used as a purification technology for mAbs in biochemistry (Ahamed et al. 2007). Interactions between protein and charged substances in IEX were influenced by oppositely charged surfaces of porous chromatographic media. The power of such interactions was supposed to be related to conductivity (Harinarayan et al. 2006). An electronegative multimodal chromatography, a significant branch of IEX, was deeply involved in the proceeding of IgG purification throughout the research.