聚乙二醇修饰固定化金属亲和介质的制备

Preparation of immobilized metal affinity media modified by polyethylene glycol

针对固定化金属离子亲和层析技术(IMAC)存在对低浓度活性小分子肽的分离特异性差、选择性低等问题,通过在固定化金属离子亲和介质表面接枝修饰聚乙二醇单甲醚(mPEG)制备磁性限进性亲和介质,并优化了接枝工艺;采用红外光谱(FTIR)、扫描电子显微镜(SEM)、热重分析(TGA)等对修饰后的介质进行了表征;以牛血清蛋白(BSA)为大分子蛋白模型,研究了不同接枝率的介质对BSA阻拒效果的影响。结果表明,当使用三氟化硼为催化剂,其用量与mPEG摩尔比为1∶0.08、反应时间为6 h、反应温度为50℃时,接枝率最大可以达到26.46%;固定化金属离子亲和介质经接枝聚乙二醇修饰后可有效减少大分子蛋白的吸附,对BSA的阻拒率最大可达到50.68%。

In order to solve the problems of low specificity and selectivity of immobilized metal ion affinity chromatography（ IMAC） technology for separation of low concentration active smallmolecular peptides in complex biological samples,the magnetic restricted access affinity adsorbent was prepared by grafting with polyethylene glycol（ m PEG） on the surface of immobilized metal ion affinity media,and the grafting process was optimized. The chemical structures were characterized by fourier transform infrared spectrometer（ FTIR）,scanning electron microscope（ SEM）,thermo gravimetric analysis（ TGA）. Bovine serum albumin（ BSA） was used as a macro-molecular protein model to study the effects of media with different grafting ratio on the blocking of BSA. The results showed that the grafting ratio reached the maximum value of 26. 46% when when the ratio of BF3 to m PEG was 1 ∶ 0. 08,the reaction time was 6 h,the reaction temperature was 50℃. Immobilized metal ion affinity media modified by polyethylene glycol could effectively reduce the adsorption of macro-molecular proteins,and the resistance ratio for BSA could reach 50. 68%.