Overexpression of full-length core protein of hepatitis C virus by Escherichia coli cultivated in stirred tank fermentor

Document Type: Research Paper

Authors

1 National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14965/161, Tehran, I.R. Iran.

2 Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), P.O. Box 15815-3538, Tehran, I.R. Iran.

3 Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, P.O. Box 14115-154, Tehran, I.R. Iran.

4 Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, I.R. Iran

Abstract

The mature core protein of the Hepatitis C virus (HCVC173) carrying pelB as a signal peptide (PelB::core) was overexpressed in Escherichia coli as 18% and 23.3% of the host’s total protein, in flask and fermentor cultivation, respectively. A final specific yield of 25 ± 1 mg HCVC173/g dry cell weight and an overall
productivity of 51±1 mg HCVC173/l/h were obtained in the stirred-tank fermentor. The recombinant
PelB::core protein was overexpressed as the inclusion body (IB) form, higher than the expected level when
compared to the HCVC173, which was also showed by the analysis of secondary structure of mRNAs and
calculation of the Codon Adaptation Index of the gene. The results showed that the combined effects of protein fusion and the signal sequence significantly enhanced the production of recombinant mature
HCVC173 in E. coli. Therefore, the fusion form of the mature HCV core protein and the conditions defined in
this study provide an alternative strategy for HCVC173 production in high cell density culture of E. coli.

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