Preparation of PEGylated Core-Shell Type Polymer Supports for Peptide Synthesis and Immunoglobulin G Purification

Abstract

Since Bruce Merrifield has introduced solid-phase peptide synthesis (SPPS) concept, various kinds of polymer supports have been developed for specific purpose. Polymer supports can be classified into gel type and core-shell type, according to the distribution of their functional groups. Reactions on the core-shell type resin are less influenced by diffusion of reagents because functional groups in the shell part are easily accessible. Therefore, core-shell type polymer support generally gives high purity of product. Meanwhile, hydrophilicity is also an important issue for bioassays, especially, on-bead ligand screening or protein immobilization. In this thesis, water compatible core-shell type resins were prepared and their applications in SPPS and protein purification were described. Series of PEG grafted polystyrene resins were prepared from aminomethyl polystyrene (AM PS) resin. Swelling properties, physical shape of the core-shell type structure and the loading levels of PEG-PS resin were investigated. After characterization, the resins were tested for the purification of IgG, via immobilization of protein A onto the resins. The performance of IgG purification was also discussed. In order to assess the performance of the resin in SPPS, model peptide sequences were synthesized on the resin and their purity and the yields were compared to the ones on HiCore® resin.