The rapidly expanding monoclonal antibody market has thrown down a great challenge to industrial production especially downstream purification in terms of its high cost and limited capacities. Recently, affinity precipitation became an attractive alternative for antibody purification to achieve simple process, high throughput, and cost reduction. While the screening and identification of a ligand that can specifically interact with a protein of interest presents a key step towards the success of this strategy, the presentation of the identified ligand on a precipitant are equally essential to realize the desired function. In this context, we report our recent progress in the development of co-assembled peptide immunofibers, composed of ligand molecules and spacer molecules, that can specifically capture and precipitate human immunoglobulin G (IgG). The ligand density can be modulated by tuning the ratio of the two components in the immunofiber system, which was demonstrated to play an important role in the IgG capture and precipitation yield. Fundamental studies were conducted such as critical micelle concentration (CMC) measurement and transmission electron microscopy (TEM) to investigate the structural differences in the co-assembled immunofiber system at different ligand densities. The impact of ligand density on binding affinity between IgG and the co-assembled peptide immunofibers were also explored using isothermal titration calorimetry (ITC). As a proof of concept, the feasibility of using co-assembled immunofiber system for antibody purification was tested with purified IgG and IgG at clarified bulk state and promising yields were obtained. Our results showed the potential use of the co-assembled immunofiber system in non-chromatography purification of monoclonal antibodies via affinity precipitation.<br/><br/>

Co-assembled protein a mimicking peptide immunofibers for affinity precipitation of monoclonal antibodies

2019 Spring National Meeting

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