Synthesis of nonlinear polymer brushes on magnetic nanoparticles as an affinity adsorbent for His-tagged xylanase purification

In this article, the magnetic nanospheres bonded to a polymer chelator have synthesized through a new strategy consisted of four parts: (1) synthesis and surface modification of nanoparticles with vinyl groups; (2) grafting of a water-soluble polymer having hydroxyl groups, by polymerization of the resulting monomer from the reaction of glycidyl methacrylate (GMA) and diethanolamine (DEA) on the surface of nanomagnetic particles; (3) by cerium(IV), conversion of hydroxyl groups of the synthesized polymer on the nanoparticles to radicals for subsequent grafting of the resulting monomer from reaction of GMA and iminodiacetic acid (IDA); and (4) in an ion-exchange process, nickel ions along the last synthesized polymer were immobilized. The prepared nanospheres were successfully used directly for purification of His-tagged xylanase from cell lysates. The separated proteins were subjected to enzyme assays and are observed well in the enzymatic activity.