1. A new vector for heterologous gene expression in Escherichia coli with increased stability in the absence of antibiotic.
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Eguia, Fara Amelia Primelles, Ramos, Henrique Roman, Kraschowetz, Stefanie, Omote, Daniel, Ramos, Celso Raul Romero, Ho, Paulo Lee, Carvalho, Eneas, and Gonçalves, Viviane Maimoni
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ESCHERICHIA coli physiology , *GENE expression in bacteria , *ANTIBIOTICS , *PROTEIN synthesis , *PLASMID genetics - Abstract
Abstract Expression vectors for industrial production should be stable and allow tight control of protein synthesis. This is necessary to ensure plasmid transmission to daughter cells in order to achieve a stable population capable of synthesizing high amounts of the target protein. A high-copy-number plasmid, pAE, was previously used for laboratory-scale production of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and the Schistosoma mansoni fatty acid binding protein (rSm14), but it was unstable for large-scale production. Therefore, here we evaluated a new expression vector derived from pAE, pAR-KanI, which combines two plasmid replication strategies: a high-copy plasmid pUC origin of replication as pAE, and a par locus sequence derived from pSC101, which is typical of low copy plasmids, for rhG-CSF and rSm14 production in Escherichia coli. Clones bearing these constructs were cultivated in two complex media (2YT and auto-induction) and both yielded higher-than-95% resistant colonies, before and after induction, either with or without antibiotics. In 2YT medium, we obtained 244 μg/mL of rSm14, 181 μg/mL and 392 μg/mL for rhG-CSF, with and without glucose, respectively. In auto-induction medium without antibiotics, 147 μg/mL of rSm14 and 162 μg/mL of rhG-CSF were obtained. The new vector presented high stability for the production of both recombinant proteins in complex media in Escherichia coli , even in the absence of antibiotics, making the pAR-KanI a promising vector for industrial production of recombinant proteins. Highlights • The effect of a par locus insertion into a high copy number plasmid on the stability was evaluated. • The novel expression vector pAR-KanI presented high stability in E. coli c ultivated in complex media without antibiotics. • pAR-KanI was successfully employed for production of two important molecules: rhG-CSF and rSm14. • The absence of antibiotics is important to reduce the costs of the recombinant protein production process. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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