The Over-Expression of Biologically Active Human Growth Hormone in a T5-Based System in Escherichia coli, Studying Temperature Effect
نویسندگان : A. Zomorrodipour B. Yakhchali M. Khodabandeh A. Deezagi S.M. Hosseini Mazinani S. Valian Borujeni M. Ahmadzadeh Raji M. Rahimi H. Ahmadi Danesh M.H. Sanati
We studied the expression of human growth hormone (hGH) in E. coli under a bacteriophage T5-base promoter in a pQE30 expression vector. For an efficient expression of hGH cDNA, a number of codons at the hGH N-terminal coding region were altered based on the E. coli major codons. An over-expression of hGH in the bacteria, carrying the recombinant plasmids, was observed at 37°C in the presence of IPTG. The over-expression was also observed at 30°C in the absence of IPTG. Therefore a temperature down-shift induction, 37°C to 30°C, was suggested to achieve an over-expression of recombinant hGH (rhGH) without the use of chemical inducers. The pQE30-hGH recombinant plasmids show high stability in the TG1 host in the non-selective conditions. In a batch fermentation condition, the purified rhGH was obtained with the yield of 53 mg/l of culture. We took advantage of the formation of inclusion bodies to recover the rhGH, followed by diafiltration and refolding steps. The purified rhGH was biologically active for its receptor-binding on IM9 cells
کلید واژگان :Recombinant human growth hormone; T5 promoter; Escherichia coli; Inclusion body; Batch fermentation; Receptor binding assay
ارزش ریالی : 600000 ریال
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