A novel mutant recombinant human growth hormone (rhGH) production in Escherichia coli via genetic modifications

Document Type : Research Paper

Authors

Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran

Abstract

Human growth hormone (hGH) (also called somatotropin) is a single-chain polypeptide that is made and secreted into the blood circulation by the anterior part of the pituitary gland. The growth hormone is composed of 191 amino acids, two disulfide bonds, and four α-helices. Based on crystallographic studies, one hGH binds to two growth hormone receptors and forms a ternary complex. The hGH has two receptor-binding sites: site1 (high affinity) and site2 (low affinity). The primary objective of the present study was to enhance the binding affinity of receptor-binding site 1 through targeted substitution of eight specific amino acid residues (Arginine, lysine, aspartic acid, lysine, glutamine, histidine, isoleucine, and histidine with asparagine, alanine, serine, arginine, serine, asparagine, threonine, and aspartic acid). For this aim, the GH1 gene (which encodes hGH) was manipulated by introducing mutations (missense) using polymerase chain reaction (PCR). Then, mutant GH1 was cloned into the pGH vector (a plasmid vector) and, after propagation (in Escherichia coli DH5α), was subcloned into the pCold vector and expressed in Escherichia coli. The Western Blot technique was used to determine the production of mutant hGH. Protein purification and quantitative assessment were performed using Nickel-Sepharose affinity chromatography and Bradford assay, respectively. The biological activity of the mutant hGH was examined using the Ba/F3-rat-GHR cell line, which stably expresses the human growth hormone receptor (hGHR). Molecular docking analysis using HADDOCK indicated that the mutant hGH exhibited a higher binding affinity for hGHR compared to the wild-type hormone. Two recombinant growth hormones (R-GH1 and R-GH2) were obtained. Results suggested that recombinant hGHs induced the proliferation of Ba/F3-rat-GHR cell lines more potently than commercial (Zorbtive) hGH (P< 0.05). This study successfully engineered a mutant form of hGH with enhanced receptor-binding affinity, improved in vitro biological activity, and greater proliferative potency compared to commercial hGH, suggesting its potential for therapeutic applications.

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Bergamaschi, L. M. F. T. R., Torella, E. S. F. M. M., & Cicognani, E. B. A. (2009). Developmental syndromes: growth hormone deficiency and treatment. Endocrine Involvement in Developmental Syndromes, 14, 114–134. doi: 10.1159/000207481.
Cho, H., Daniel, T., Buechler, Y. J., Litzinger, D. C., Maio, Z., Putnam, A.-M. H., Kraynov, V. S., Sim, B.-C., Bussell, S., & Javahishvili, T. (2011). Optimized clinical performance of growth hormone with an expanded genetic code. Proceedings of the National Academy of Sciences, 108(22), 9060–9065. doi: 10.1073/pnas.1100387108.
Choi, T.-J., & Geletu, T. T. (2018). High level expression and purification of recombinant flounder growth hormone in E. coli. Journal of Genetic Engineering and Biotechnology, 16(2), 347–355.
De Vries, S. J., Van Dijk, M., & Bonvin, A. M. J. J. (2010). The HADDOCK web server for data-driven biomolecular docking. Nature Protocols, 5(5), 883–897. doi:10.1038/nprot.2010.32.
Dehkhoda, F., Lee, C. M. M., Medina, J., & Brooks, A. J. (2018). The growth hormone receptor: mechanism of receptor activation, cell signaling, and physiological aspects. Frontiers in Endocrinology, 9, 35. https://doi.org/10.3389/fendo.2018.00035
Gahete, M. D., Durán‐Prado, M., Luque, R. M., Martínez‐Fuentes, A. J., Quintero, A., Gutiérrez‐Pascual, E., Córdoba‐Chacón, J., Malagón, M. M., Gracia‐Navarro, F., & Castano, J. P. (2009). Understanding the multifactorial control of growth hormone release by somatotropes: lessons from comparative endocrinology. Annals of the New York Academy of Sciences, 1163(1), 137–153. doi: 10.1111/j.1749-6632.2008.03660.x.
Ghavim, M., Abnous, K., Arasteh, F., Taghavi, S., Nabavinia, M. S., Alibolandi, M., & Ramezani, M. (2017). High level expression of recombinant human growth hormone in Escherichia coli: crucial role of translation initiation region. Research in Pharmaceutical Sciences, 12(2), 168–175. doi: 10.4103/1735-5362.202462.
Jamil Sami, A. (2007). Structure-function relation of somatotropin with reference to molecular modeling. Current Protein and Peptide Science, 8(3), 283–292. doi:10.2174/138920307780831820.
Kaabi, Y. A. (2012). Growth hormone and its receptor: a molecular insight. Saudi Journal for Health Sciences, 1(2), 61–68. DOI:10.4103/2278-0521.100942.
Kautsar, A., Wit, J. M., & Pulungan, A. (2019). Isolated growth hormone deficiency type 2 due to a novel GH1 mutation: a case report. Journal of Clinical Research in Pediatric Endocrinology, 11(4), 426. doi:10.4274/jcrpe.galenos.2019.2018.0305.
Kucharska, A., Witkowska-Sędek, E., Erazmus, M., Artemniak-Wojtowicz, D., Krajewska, M., & Pyrżak, B. (2024). The effects of growth hormone treatment beyond Growth Promotion in patients with genetic syndromes: a systematic review of the literature. International Journal of Molecular Sciences, 25(18), 10169. doi:10.3390/ijms251810169.
Lauck, F., Smith, C. A., Friedland, G. F., Humphris, E. L., & Kortemme, T. (2010). RosettaBackrub—a web server for flexible backbone protein structure modeling and design. Nucleic Acids Research, 38(suppl_2), W569–W575. https://doi.org/10.1093/nar/gkq369
Mojarrad, M., Momeny, M., Mansuri, F., Abdolazimi, Y., Tabrizi, M. H., Ghaffari, S. H., Tavangar, S. M., & Modarressi, M. H. (2010). Autocrine human growth hormone expression leads to resistance of MCF-7 cells to tamoxifen. Medical Oncology, 27(2), 474–480. DOI: 10.1007/s12032-009-9237-5
Nguyen, M. T., Koo, B.-K., Thi Vu, T. T., Song, J.-A., Chong, S.-H., Jeong, B., Ryu, H.-B., Moh, S.-H., & Choe, H. (2014). Prokaryotic soluble overexpression and purification of bioactive human growth hormone by fusion to thioredoxin, maltose binding protein, and protein disulfide isomerase. PloS One9(3), e89038. DOI: 10.1371/journal.pone.0089038
Pan, P., & Huang, X. (2022). The clinical application of growth hormone and its biological and molecular mechanisms in assisted reproduction. International Journal of Molecular Sciences, 23(18), 10768. DOI: 10.3390/ijms231810768
Ranke, M. B., & Wit, J. M. (2018). Growth hormone—past, present and future. Nature Reviews Endocrinology, 14(5), 285–300. DOI: 10.1038/nrendo.2018.22
Ross, R. J. M., Leung, K. C., Maamra, M., Bennett, W., Doyle, N., Waters, M. J., & Ho, K. K. Y. (2001). Binding and functional studies with the growth hormone receptor antagonist, B2036-PEG (pegvisomant), reveal effects of pegylation and evidence that it binds to a receptor dimer. The Journal of Clinical Endocrinology & Metabolism, 86(4), 1716–1723. DOI: 10.1210/jcem.86.4.7403
Verma, S., & Pandey, A. V. (2025). Structural and Evolutionary Analysis of Human Growth Hormone Variants. BioRxiv, 2003–2025. https://doi.org/10.1101/2025.03.19.644177
Wang, T., Zhao, B., & Foehr, E. D. (2019). Engineering a long lasting tethered, multimeric human growth hormone protein to improve pharmacokinetic half-life and potency. Journal of Proteomics & Bioinformatics, 12, 56–60. doi: 10.35248/0974-276X.19.12.497