Adsorption Characteristics of Human Immunoglobulin G on Five New Tetrapeptide Biomimetic Affinity Resins

Abstract

Alternative antibody-binding affinity ligands are expected to support robust time-and cost-effective antibody purification with rapid improvement of upstream productivity and demand on downstream process optimization. Five new tetrapeptide biomimetic affinity ligands (FYRH, HWRH, YHRI, HYRF, and FHRA) were screened by modeling the molecular interaction mechanism between tetrapeptide ligands and the Fc fragment of IgG with molecular dynamics simulation and the flexible docking method, and the corresponding five resins were prepared in this work to evaluate their adsorption characteristics of human immunoglobulin G (hIgG). The results showed that the binding capacities to hIgG of the five resins showed a strong pHdependency, which was high at pH 7.0−9.0, and extremely low at pH 5.0−6.0, providing a benefit choice to separate hIgG. The dynamic binding capacities (DBC) at 10% breakthrough of five resins could reach up to 28−37 mg/mL gel , and Ac-FYRH-4FF resin showed the best adsorption performance. The elution test results with Ac-FYRH-4FF resin indicated that hIgG could be eluted mildly at pH 5.0 with a 96.5% recovery, meaning that this resin can be considered as a powerful candidate of alternative biomimetic affinity chromatographic resin.

A novel dextran‐grafted tetrapeptide resin for antibody purification

“…The results of Section 3.3 showed pH 9.0 was the optimal condition for the binding of the resin and hIgG. Moreover, the condition of pH 9.0 has commonly used in antibody separation [4,24,25]. For example, Tuhidul Islam et al.…”

“…[25] used 0.1 M Tris HCl pH 9.0 as optimal washing buffer for HWRGWV‐TREN‐WB resin to purify therapeutic monoclonal IgG1 and Zhu et al. [24] discovered tetrapeptide biomimetic affinity resins could be well used for hIgG purification at pH 9.0. Therefore, the separation performance of the Ac‐YFRH‐XL resin was pH 9.0, and this weak alkaline condition could isolate proteins that are not easily separated under neutral or acidic conditions without affecting their activity [4,24].…”

“…[24] discovered tetrapeptide biomimetic affinity resins could be well used for hIgG purification at pH 9.0. Therefore, the separation performance of the Ac‐YFRH‐XL resin was pH 9.0, and this weak alkaline condition could isolate proteins that are not easily separated under neutral or acidic conditions without affecting their activity [4,24]. The ligand density of the resin for separation was 114 µmol/g resin that made it convenient for comparison to non‐grafted resin (101 µmol/g resin).…”

“…The experiment was conducted in triplicate to get the ionic capacity of the resin calculated by mass balance. The amino density was described by equation (Equation ) as, where ρ 1 is the amino density of the resin (µmol/g resin), c is the concentration of the HCl solution (mol/L), V is the volume of the HCl solution (mL), and m is the mass of the resin (g), respectively [24].…”

“…Moreover, the most serious environmental (pH 9.0) chosen in this article was discovered as a common condition used in antibody purification. And this condition could separate protein that cannot be easily separated under neutral or acidic conditions without damaging its structure [4,24,25].…”