Fig. 3

Engineering secretory expression of TGm1 in E. coli. A Engineering the periplasmic activation of TGm1; B The lowest (Top) and highest (Bottom) 10 mRNA folding energy pelB sequence variants achieved by codon shuffling. C The intracellular and extracellular activity of TGm1 fused with different pelB sequence variants. Statistically significant differences were determined using Excel Variance Analysis, and the p value comparison between Top-9 and Δlpp-Top-9 is displayed and indicated with an asterisk. Native: TGm1 fused with the pelB from pET-22b (+). Δlpp-Top-9: TGm1 fused with the Top-9 pelB, and the plasmid was transformed into E. coli Δlpp. Each recombinant E. coli was cultivated in TB medium at 20 ℃ for 40 h after 0.1 mM IPTG addition