Cloning and Expression of Recombinant Human Growth Hormone in E. coli: High-Yield Production and Biological Activity Assessment

Document Type : New and original researches in the field of Microbiology.

Authors

1 Master Degree Student, Biotechnology Department, Faculty of Science, Cairo University

2 Associate Professor, Biochemistry and Molecular Biology Department, Theodor Bilharz Research Institute, Giza, Egypt

3 Professor of Organic Chemistry, Faculty of Science, Cairo University

4 Professor of Molecular Biology, Department of Zoology, Faculty of Science, Cairo University

5 5Associate Professor, Department of Biochemistry and Molecular Biology, Theodor Bilharz Research Institute, Giza, Egypt; Postal address: 12411; Vice Dean School of Biotechnology, Badr University in Cairo, Badr City, Cairo 11829, Egypt

Abstract

Background: The Human Growth Hormone (HGH) is a pituitary gland secretion hormone that stimulates cell division, growth, and repair in humans and animals. It Fis a protein with a molecular weight (MW) equal to 22 kDa. Objectives: Production of HGH in prokaryotic expression system via synthetic gene coding design for HGH. Methodology: Cloning the HGH-designed coding sequence in a pET-3a expression vector for protein synthesis in BL21 DE3 E. coli strain. The expressed recombinant HGH (rHGH) at the batch fermentation level was purified according to HGH MW and its biological activity was assayed. Results: 24 h batch fermentation showed a bacterial growth at OD595 equal to 1.6 ± 0.023 and the wet cell weight (WCW) was 16.4 ± 0.32 gm/L. Immunodetection confirmation of rHGH using Western blot showed a 22 kDa band at the expected MW. Purification of HGH using anion exchange chromatography revealed a concentration of purified rHGH of about 480.22 µg/ml. Using normal Vero cells, the activity of purified rHGH was 0.228 IU/mg. Conclusion: Native rHGH protein was produced at a large scale with potential biological activity compared to standard HGH; somatotropin, using modern technologies in recombinant DNA.

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