title: Peptide-based immunoadsorbents: molecular grafting of IgG-Fc-binding epitopes of Protein A onto a de novo-designed helix-loop-helix peptide.
abstract: The development of immunoadsorbents that have high specificity for immunoglobulin and no immunogenicity is essential for immunoadsorption treatment of autoimmune diseases. In this study, we designed peptide immunoadsorbents by molecular grafting of the IgG-Fc binding epitopes of Protein A onto a de novo-designed helix-loop-helix peptide. Linear (linG7A5) and cyclic (cyG7A5) grafted peptides were synthesized to test their binding affinity and specificity. Peptide cyG7A5 demonstrated high specificity for human IgG-Fc, with a K(D) of 19 μM, and demonstrated no affinity to other plasma proteins, human serum albumin, or fibrinogen. To evaluate their immunoadsorbance efficiency, the grafted peptides and Protein A were conjugated to polyvinyl acetate resin and tested in a batch-wise process for adsorption removal of IgG from human plasma. The IgG capture capacities of the peptides correlated well with their binding affinities. Interestingly, cyG7A5 showed a higher binding specificity for IgG than did Protein A.
authors.affiliation: Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Kawabata
authors.affiliation: Asahikasei Medical Co., Ltd, 1-105 Kanda Jinbocho, Chiyoda-ku, Tokyo 101-8101, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nagai
authors.affiliation: Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Konishi
authors.affiliation: Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fujiwara
authors.affiliation: Asahikasei Medical Co., Ltd, 1-105 Kanda Jinbocho, Chiyoda-ku, Tokyo 101-8101, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Sasaki
authors.affiliation: Asahikasei Medical Co., Ltd, 1-105 Kanda Jinbocho, Chiyoda-ku, Tokyo 101-8101, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ichikawa
authors.affiliation: Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan. Electronic address: fujii@b.s.osakafu-u.ac.jp.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Fujii
mesh_terms: D000327:Adsorption; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000097:blood / Q000737:chemistry*; D007164:Immunosorbents / Q000138:chemical synthesis / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D013205:Staphylococcal Protein A / Q000737:chemistry*
chemical_list: D007140:Immunoglobulin Fab Fragments; D007164:Immunosorbents; D010455:Peptides; D013205:Staphylococcal Protein A
keywords: Helix-loop-helix peptide; Human IgG–Fc; Immunoadsorption; Protein grafting; Protein–protein interaction