Preparation of a modified crosslinked chitosan/polyvinyl alcohol blended affinity membrane for purification of His‐tagged protein

Based on a crosslinked chitosan (CS)/polyvinyl alcohol (PVA) matrix membrane, an immobilized metal ion affinity membrane (IMAM) using Cu 2+ and Ni 2+ ions as affinity ligands was prepared for purification of the His‐tagged recombinant protein. The affinity membrane possessed a favorable membrane structure including 1.39 μm average pore size and 0.33 mL·cm −2 ·s −1 water flux under 0.08 MPa pressure at 25 °C. The Cu 2+ and Ni 2+ ions capacities immobilized on the IMAM were 155.6 and 137.3 μmol·disk −1 , respectively. The IMAM had an excellent specific affinity to His‐tagged protein. About 10‐fold purification factor for the model protein was obtained in a batch adsorption, and serine hydroxymethyl transferase could be purified to a single band in sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis from its crude extract solution with an affinity membrane cartridge by a dynamic purification process. This work provides a promising IMAM for the purification of His‐tagged recombinant proteins. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47347.