Identification of a peptide ligand for antibody immobilization on biosensor surfaces

• Published in: Biochip journal 2016, 10(2), , pp.88-94
• Main Authors: Yoo, Ran-Ji, Choi, Suk-Jung
• Format: Article
• Language: English
• Subjects: Antibodies; Binding; Biomedical Engineering and Bioengineering; Biosensors; Biotechnology; Chemistry; Chemistry and Materials Science; Enzyme immunoassay; IgG antibody; Immobilization; Immunoassay; Immunoglobulin G; Ligands; Nucleotides; Original Article; Peptide libraries; Peptides; Phages; Protein A; Quartz crystal microbalance; Quartz crystals; Rabbits; 생물공학
• ISSN: 1976-0280; 2092-7843
• DOI: 10.1007/s13206-016-0202-z

The construction of biosensors with antibodies as the biological sensing element requires the integration of antibodies into the biosensor such that their activity is reproducibly retained. In this work, a peptide ligand was identified from phage-displayed heptameric peptide libraries for the purpose of antibody immobilization on biosensor surfaces. For biopanning of peptides specific to the Fc region of the antibody, rabbit anti-goat immunoglobulin G (IgG) antibody was immobilized on a culture dish coated with goat IgG, which enabled exposure of the F c region of rabbit antibody on the surface with the F ab region bound to the surface-adsorbed goat IgG. The library phages were added to the dish and phages displaying antibody-binding peptides were competitively eluted using the rabbit antibody. After four rounds of biopanning, 22 phage plaques were randomly selected and their nucleotide sequences corresponding to the random peptide were determined. Three enriched sequences were selected and analyzed for their rabbit antibody-binding activity. One of these sequences (KHRFNKD), which was rich in positive charge and homologous to the IgG-binding domains of Staphylococcal protein A, exhibited a high and specific affinity to rabbit antibody. This peptide was immobilized on a quartz crystal microbalance (QCM) biosensor, and the resulting QCM was found to be capable of capturing antibody and detecting antigen, with potential applications in antibody purification and enzyme immunoassay.