Reversible Concanavalin A (Con A) ligands immobilization on metal chelated macroporous cellulose monolith and its selective adsorption for glycoproteins.

The present work deals with the development of novel affinity monolith with reversible protein ligands for protein chromatography. As for the formation of reversible ligands, Concanavalin A (Con A) is chelated with Cu(II)-iminodiacetic acid (IDA) immobilized macroporous cellulose monolith (MCM) for glycoprotein adsorption. The reversible immobilization is realized by Cu ions, which bridge affinity ligands and support by strong chelation interaction. The fabrication process of reversible Con A immobilized adsorbent is studied, especially with regards to the effect of synthesis conditions on the ligands immobilization. The adsorption behavior is then evaluated to elucidate the potential of Con A-Cu(II)-IDA-MCM for protein chromatography. It reveals that the static adsorption capacity and dissociation constant of glucose oxidase (GOD) on Con A-Cu(II)-IDA-MCM are determined to be 17.4 ± 0.6 mg mL-1 and 0.055 ± 0.011 mg mL-1 by Langmuir model. With frontal analysis, the dynamic binding capacity of GOD at 10% breakthrough point is about 11.4 ± 1.0 mg mL-1 and changes less with an increase of flow velocity from 0.2 to 1.0 mL min-1 . Moreover, Con A-Cu(II)-IDA-MCM displays weak nonspecific adsorption for the impurities and is able to successfully enrich glycoprotein ovalbumin (OVA) from diluted chicken egg white. In addition, Con A-Cu(II)-IDA-MCM exhibits excellent stability by the repeated adsorption/desorption operations. By taking these advantages of high adsorption capacity, excellent specificity and structure stability, the prepared affinity adsorbent of Con A-Cu(II)-IDA-MCM has great potential for high performance protein chromatography.