A Single Codon Optimization Enhances Recombinant Human TNF-α Vaccine Expression in Escherichia coli

Figure 4

Expression and identification of TNF-PADRE. A and B plasmids pET-22b-rTNF-PADRE (a) and pET-22b-mrTNF-PADRE (b) were transformed into E. coli BL21 (DE3) strain and recombinant vaccine expression was induced by IPTG and detected by SDS-PAGE. Lane 1, total bacterial proteins before IPTG induction; lane 2, total bacterial proteins after IPTG induction. (c) Identification of expressed mrTNF-PADRE by Western blot. Lane 1, molecular weight standards (kDa); lane 2, total bacterial proteins after IPTG induction. (d) BL21 (DE3)/pET-22b-mrTNF-PADRE bacteria were cultured in a 5-L fermentor and mrTNF-PADRE expression was detected by SDS-PADRE. Lane 1, molecular weight standards (kDa); lane 2, total bacterial proteins without induction; lane 3–6, total bacterial proteins after 1–4 h induction. Arrowheads indicate the target protein.

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