Affinity chromatography of human IgG with octapeptide ligands identified from eleven peptide-ligand candidates

作者：Xue, Aiying; Zhao, Wei-Wei; Liu, Xiaoguang; Sun, Yan^*

来源：Biochemical Engineering Journal, 2016, 107: 18-25.

DOI：10.1016/j.bej.2015.11.020

• Protein
• Affinity
• Adsorption
• Chromatography
• Purification
• Human immunoglobulin G

We have reported earlier on the characterization of four peptides from a library of 15 peptide ligand candidates for human IgG (hIgG) obtained by a biomimetic design strategy and identified three high-affinity octapeptides. In this work, the left 11 peptides were evaluated and we found two more octapeptides (FYCHWQDE and FYCHNQDE) that showed high affinity for hIgG. The binding pH ranges for the two ligands were different, but the optimum pH values were the same for each other (pH 6.0). Both the ligands showed high specificity and bound hIgG mainly by electrostatic interactions. Ligand binding competition experiments revealed that the binding sites on hIgG for the two octapeptides were similar to those for Protein A. Finally, hIgG was purified from human serum with high purities and recovery yields with the two peptide affinity columns. Thus, among the 15 peptide candidates, a total of five octapeptides were identified as high-affinity ligands of hIgG. The five ligands were all derived from the same peptide model FYxHxxxE (where x denotes any amino acid) and contained four common hot spots F132, Y133, H137, and E143 of the affinity motif of Protein A. Analyses and evaluation of the peptide library would help deepen our understanding of the affinity binding of Protein A to IgG, and promote application of the biomimetic strategy in the design of affinity ligands for different proteins.

• 出版日期2016-3-15
• 单位天津大学