AN EFFECTIVE MAGNETIC SEPARATION TECHNIQUE FOR ANTIBODY BASED ON THIOPHILIC PARAMAGNETIC POLYMER BEADS
嗜硫类磁性聚合物微球高效分离抗体

A rapid non-chromatographic technique,based on the thiophilic magnetic beads,was exploited to purify antibodies with high purity and bioactivity.After these paramagnetic beads were synthesized with vinyl acetate and divinylbenzene by microsuspension polymerization,an effective surface modification with divinyl sulfone and 2-mercapto-pyrimidine was carried out to endow these beads with the ability to specifically capture immunoglobulin G (IgG) from human serum.The essential mechanism between the thiophilic ligands and IgG was also investigated.It was found that the specific interaction between 2-mercapto-pyrimidine and IgG mainly depended on electron donor acceptor effect,and this responding specific adsorption to IgG could be performed in a salt-independent manner.We also investigated the relevant factors influencing the isolation,such as pH value,temperature,ion kinds and ion strength.The purity of the isolated antibody exceeded 92%,with bioactivity almost fully maintained (>99%).Although the maximum yield of the isolation process was only 37.7% at NaCl concentration 0.4 mol/L,the recovery of IgG can reach 86.8% by successive extractions. The easy operation,conventional equipments and rapid process make this technique potential in large-scale purification of antibody.