嗜硫类磁性聚合物微球高效分离抗体

用微悬浮聚合技术制备微米级顺磁性的聚合物微球,并通过水解反应在其表面生成丰富的羟基,进而通过二乙烯基砜活化,在其表面修饰2-巯基嘧啶,实现磁性微球对人体免疫球蛋白G(IgG)的特异性识别.进一步探讨了不同解吸附环境,如pH值、温度、离子种类、离子强度等条件,对这种特异性吸附行为的影响.采用此磁性分离技术后,分离抗体的纯度超过92%,抗体活性高于99%.通过连续分离工艺,IgG的分离效率达到86.8%.

AN EFFECTIVE MAGNETIC SEPARATION TECHNIQUE FOR ANTIBODY BASED ON THIOPHILIC PARAMAGNETIC POLYMER BEADS

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.