Preparation of Recombinant Protein with GST and His Tag and Its ZnO-Binding Quality

The plasmid pET-28a(+) was used as templates to PCR-amplify objective fragment containing the upstream 6×Histidine sequence with designed primers. PCR products were ligated into a prokaryotic expression vector pGEX-4T-3. Positive <em<E.coli</em< clones containing recombinant plasmid pGEX-His were selected and identified, followed by transformation into <em<E.coli</em< BL21 cells and induction with IPTG. The recombinant protein GST-His was expressed with GST and His tag, purified with Ni-NTA system, identified by SDS-PAGE electrophoresis and Western blot analysis and confirmed by LC-MS/MS analysis. Affinity adsorption test on the proteins binding with nanoparticles demonstrated that the fusion protein had a specific adsorption with ZnO nanoparticles.