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Updated: Jul 17, 2026
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The Multifaceted Benefits of Protein Co-expression in Escherichia coli
Published on: February 5, 2015
[Two incompatible plasmids coexpress the human endostatin and predigested human plasminogen kringle 5 in E. coli]
Jian Sun1, Jian-Qi Wang, Zhao-Yang Zhai
1Department of Biochemistry and Molecular Biology, West China School of Preclinicial and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Summary
This study demonstrates a novel method for coexpressing human endostatin (hES) and human plasminogen kringle 5 (predhPK-5) in E. coli using two incompatible plasmids. The engineered E. coli successfully produced both recombinant proteins, showing plasmid stability under antibiotic pressure.
Area of Science:
- Molecular Biology
- Biotechnology
- Protein Expression
Background:
- Coexpression of multiple proteins in a single host is crucial for various biotechnological applications.
- Challenges exist in maintaining the stability of multiple plasmids, especially incompatible ones, within a host organism.
- Developing efficient strategies for coexpressing recombinant proteins is essential for advancing synthetic biology and therapeutic protein production.
Purpose of the Study:
- To construct the recombinant plasmid pET28a/hES for expressing human endostatin (hES).
- To coexpress hES and predigested human plasminogen kringle 5 (predhPK-5) in E. coli.
- To assess the feasibility and stability of coexpressing proteins from two incompatible plasmids in E. coli.
Main Methods:
- Human endostatin gene was amplified from liver mRNA and cloned into pET-28a(+).
- E. coli BL21 (DE3) was cotransformed with pET28a/hES and pGEX-1lambdaT/predhPK-5.
- Recombinant protein expression was induced using IPTG, and plasmid stability was monitored under ampicillin and kanamycin selection.
Main Results:
- The two incompatible plasmids, pET28a/hES and pGEX-1lambdaT/predhPK-5, were successfully maintained in E. coli under dual antibiotic pressure.
- Coexpression of hES and predhPK-5 was achieved, with recombinant proteins constituting approximately 20% and 21% of total cell proteins, respectively.
- The cotransformants remained stable, with over 75% of cells maintaining both plasmids after 16 hours or 120 passages.
Conclusions:
- A feasible method for coexpressing recombinant proteins from two incompatible plasmids in E. coli has been established.
- This approach facilitates the simultaneous production of human endostatin and human plasminogen kringle 5.
- The findings offer a new strategy for protein coexpression in microbial hosts, enhancing biotechnological applications.
