Effect of spacer-arm and Cu(II) ions on performance of l-histidine immobilized on poly(GMA/MMA) beads as an affinity ligand for separation and purification of IgG

In this study, the beads were prepared from glycidiyl methacrylate (GMA) and methyl methacrylate (MMA) via suspension polymerization and, the used beads fractions were between 75 and 150 μm. The epoxy groups of the beads were converted into amino groups by the reaction of ammonia or 1,6-diaminohexane as a spacer-arm. l-Histidine ligand was immobilized onto both beads. Cu(II) ions were chelated onto spacer-arm attached and l-histidine immobilized beads. The IgG adsorption capacity of the spacer-arm attached and Cu(II) chelated affinity beads led to higher adsorption capacities about 1.64- and 2.94-fold, respectively. The adsorption equilibrium studies showed that the adsorption isotherm of IgG obeyed the Langmuir isotherm model. The experimental data was well described by the second-order equations. Purification data of IgG with spacer-arm attached and Cu(II) ions chelated (i.e. poly(GMA/MMA)-SAH-Cu(II)) beads indicated that 87.5% of IgG was removed from human serum with a purity of 90%.