Figure 3 | Scientific Reports

Figure 3

From: Improvement in the production of the human recombinant enzyme N-acetylgalactosamine-6-sulfatase (rhGALNS) in Escherichia coli using synthetic biology approaches

Figure 3

Production of rhGALNS in E. coli BL21(DE3) with cultures exposed to high osmotic stress. (A) Specific activity in the extracellular fraction. (B) Volumetric activity in the extracellular fraction. (C) Specific activity in the intracellular fraction. (D) Volumetric activity in the intracellular fraction. Enzyme activity was assessed 24 hours after induction. A Student’s t-test was performed to assess significance, where (*) corresponds to a p-value < 0.05 and (****) p-value < 0.0001. Specific activities are expressed as U rhGALNS/(mg total protein) and volumetric activities as U/ml. (E) Western-blot of rhGALNS levels in the intracellular and insoluble protein fractions using high osmotic stress, with production controlled by the promoter tac using optimal (0.5 mM) IPTG concentration. The results showed a significant increase of rhGALNS protein in both, intracellular and solubilized protein aggregates fraction under tac control supplemented with 5% of sucrose. In addition, increased expression was observed in both processed and mature protein.

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