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 Cu2+ and Ni2+ 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 mu m average pore size and 0.33 mL.cm(-2).s(-1) water flux under 0.08 MPa pressure at 25 degrees C. The Cu2+ and Ni2+ ions capacities immobilized on the IMAM were 155.6 and 137.3 mu mol.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. (C) 2018 Wiley Periodicals, Inc.