title: Development of the Double Cyclic Peptide Ligand for Antibody Purification and Protein Detection.
abstract: Development of a peptide-based affinity matrix and detection reagent is important for biomedical research and the biopharmaceutical industry. In the present work, we designed and synthesized an immunoglobin G (IgG)-binding peptide ligand, Fc-III-4C. Fc-III-4C is composed of 15 residues, and the 4 cysteine residues form 2 disulfide bonds to generate a double cyclic structure. The binding affinity of the Fc-III-4C peptide toward human IgG was determined to be 2.45 nM (Kd), which is higher than that of IgG with Protein A/G (Pro-A/G). Importantly, the Fc-III-4C peptide displayed high affinity to various IgGs from different species. Fc-III-4C immobilized agarose beads exhibited high stability and reusability when compared with that of the Pro-A/G-immobilized beads. The conjugate of Fc-III-4C with FITC was demonstrated to be suitable for immunofluorescence detection of proteins expressed in cells. These results demonstrate that the Fc-III-4C peptide is a useful affinity ligand for antibody purification and as a protein detection reagent.
authors.affiliation: MOE Key Laboratory of Bioinformatics, School of Life Sciences and ‡Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University , Beijing, China , 100084.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Gong
authors.affiliation: MOE Key Laboratory of Bioinformatics, School of Life Sciences and ‡Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University , Beijing, China , 100084.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Bioinformatics, School of Life Sciences and ‡Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University , Beijing, China , 100084.
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Bioinformatics, School of Life Sciences and ‡Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University , Beijing, China , 100084.
authors.forename: Shan
authors.initials: S
authors.lastname: Feng
authors.affiliation: MOE Key Laboratory of Bioinformatics, School of Life Sciences and ‡Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University , Beijing, China , 100084.
authors.forename: Haiteng
authors.initials: H
authors.lastname: Deng
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation
chemical_list: D007074:Immunoglobulin G; D008024:Ligands; D010456:Peptides, Cyclic