Expression of recombinant TAT-Apoptin
protein in the different E. coli strains. The TAT-Apoptinopt protein was expressed in the E. coli strains BL21(DE3) and BL21(DE3)pLysS, which contained either pET-TAT-VP3opt or pGEX-TAT-VP3opt, at 37 °C. His-TAT-Apoptinopt and GST-TAT-Apoptinopt protein were examined and detected using SDS-PAGE (A, C) and Western-blotting (B, D). Anti-His and anti-GST tag monoclonal antibodies was respectively used to recognize the His-TAT-Apoptinopt protein and GST-TAT-Apoptinopt. Lane M, pre-stained protein marker; “-” and “+” represented pre-induction and post-induction with 1 mM of IPTG over 4 hrs of cultivation in E. coli, respectively.