Heu, Woosung Choi, Jung-Min Lee, Joong-Jae Jeong, Sukyo Kim, Hak-Sung Protein Binder for Affinity Purification of Human Immunoglobulin Antibodies The importance of a downstream process for the purification of immunoglobulin antibodies is increasing with the growing application of monoclonal antibodies in many different areas. Although protein A is most commonly used for the affinity purification of antibodies, certain properties could be further improved: higher stability in alkaline solution and milder elution condition. Herein, we present the development of Fc-specific repebody by modular engineering approach and its potential as an affinity ligand for purification of human immunoglobulin antibodies. We previously developed the repebody scaffold composed of Leucine-rich repeat (LRR) modules. The scaffold was shown to be highly stable over a wide range of pH and temperature, exhibiting a modular architecture. We first selected a repebody that binds the Fc fragment of human immunoglobulin G (IgG) through a phage display and increased its binding affinity up to 1.9 × 10<sup>–7</sup> M in a module-by-module approach. The utility of the Fc-specific repebody was demonstrated by the performance of an immobilized repebody in affinity purification of antibodies from a mammalian cell-cultured medium. Bound-antibodies on an immobilized repebody were shown to be eluted at pH 4.0 with high purity (>94.6%) and recovery yield (>95.7%). The immobilized repebody allowed a repetitive purification process more than ten times without any loss of binding capability. The repebody remained almost intact even after incubation with 0.5 M NaOH for 15 days. The present approach could be effectively used for developing a repeat module-based binder for other target molecules for affinity purification. Human Immunoglobulin AntibodiesThe importance;approach;affinity purification;LRR;antibody;0.5 M NaOH;immunoglobulin antibodies;repebody 2014-06-17
    https://acs.figshare.com/articles/journal_contribution/Protein_Binder_for_Affinity_Purification_of_Human_Immunoglobulin_Antibodies/2281858
10.1021/ac501158t.s001