A megaporous material harbouring a peptide ligand for affinity IgG purification

Common limitations of Protein A affinity chromatography include high adsorbent costs, ligand instability and possible ligand leakage. In this study, a short peptide with affinity for IgG was synthesized chemically and subsequently immobilized on a megaporous support. The support was prepared utilising the cryogel technique while the peptide‐ligand was covalently immobilised via thiol‐epoxy click chemistry. The cryogel support was chemically grafted to increase the number of reaction sites. This adsorbent was designated as “MP‐Pep”. Adsorption isotherms were employed to evaluate protein binding capacity. A maximum static binding capacity within the range of 30–60 mg/mL was observed for ThIgG. This parameter compares well with other commercial and non‐commercial adsorbents, as reported in the literature. As a control material, a Protein A grafted megaporous cryogel was synthesized. Dynamic binding capacity values were obtained by breakthrough analysis. The peptide cryogel showed a dynamic capacity value 9.0 mg/mL in comparison to 9.7 mg/mL in the case of the Protein A based adsorbent. The ratio of dynamic binding capacity to static binding capacity was 20%, indicating suboptimal product capture. However, the advantage of MP‐Pep lies in its cost‐effective preparations while maintaining a reasonable binding capacity for the targeted product. The presence of cooperative effects during protein binding could also represent an advantage during the processing of a feedstock containing a product in high concentration.