Importance of surface properties of affinity resin for capturing a target protein, Cyclooxygenase-1

We have prepared affinity resins based on two kinds of solid phases, including a commercially available solid phase, to re-realize the importance of surface properties of affinity resins such as controlled ligand density as well as existential surroundings of the ligand. Affinity resins were prepared using non-steroidal anti-inflammatory drugs, such as Ketoprofen, Ibuprofen, and Aspirin, having different activities as ligands. The ligand density was controlled through two different strategies: one strategy was that the solid phases having different amino group densities (20, 60, 100, 125 μmol/ml) were utilized then, Ketoprofen was fully immobilized through condensation reaction to amino groups; another strategy was that a solid phase having amino group density (125 μmol/ml) was utilized then, each ligand was immobilized with controlled immobilization rate. In addition, a typical hydrophobic group, stearoyl group (C18 group), was immobilized on the affinity resin with controlled ligand immobilization rate to change the existential surroundings of the ligand. Affinity tests were performed for Cyclooxgenase-1 (COX-1) as it was the target protein in this work. The amount of captured COX-1 was evaluated utilizing each affinity resin. It was suggested that the density of surface ligand tends to relate to the amount of captured COX-1 on our solid phase-based affinity resins; however, several exceptions occurred according to the surface properties of affinity resins in the case of commercial one.