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BioMed Research International
Volume 2016, Article ID 3758941, 7 pages
http://dx.doi.org/10.1155/2016/3758941
Research Article

High Efficient Expression, Purification, and Functional Characterization of Native Human Epidermal Growth Factor in Escherichia coli

1School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
2Guangdong Province Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, China

Received 25 July 2016; Accepted 5 September 2016

Academic Editor: Jiazhang Lian

Copyright © 2016 Yi Ma et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Human epidermal growth factor (hEGF) is a small, mitotic growth polypeptide that promotes the proliferation of various cells and is widely applied in clinical practices. However, high efficient expression of native hEGF in Escherichia coli has not been successful, since three disulfide bonds in monomer hEGF made it unable to fold into correct 3D structure using in vivo system. To tackle this problem, we fused Mxe GyrA intein (Mxe) at the C-terminal of hEGF followed by small ubiquitin-related modifier (SUMO) and 10x His-tag to construct a chimeric protein hEGF-Mxe-SUMO-H10. The fusion protein was highly expressed at the concentration of 281 mg/L and up to 59.5% of the total cellular soluble proteins. The fusion protein was purified by affinity chromatography and 29.4 mg/L of native hEGF can be released by thiol induced N-terminal cleavage without any proteases. The mitotic activity in Balb/c 3T3 cells is proliferated by commercial and recombinant hEGF measured with methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay which indicated that recombinant hEGF protein stimulates the cell proliferation similar to commercial protein. This study significantly improved the yield and reduced the cost of hEGF in the recombinant E. coli system and could be a better strategy to produce native hEGF for pharmaceutical development.