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A Convenient and General Expression Platform for the Production of Secreted Proteins from Human Cells
Published on: July 31, 2012
Expression system for recombinant human growth hormone production from Bacillus subtilis
Tunçer H Ozdamar1, Birgül Sentürk, Ozge Deniz Yilmaz
1Biochemical Reaction Engineering Laboratory, Chemical Engineering Dept., Ankara University, 06100 Ankara, Turkey. ozdamar@eng.ankara.edu.tr
Biotechnology Progress
|February 19, 2009
Summary
Researchers developed a novel Bacillus subtilis expression system to produce human growth hormone (hGH). This system successfully secreted native hGH, achieving high yields and demonstrating potential for heterologous protein production.
Area of Science:
- Biotechnology
- Molecular Biology
- Microbial Engineering
Background:
- Bacillus subtilis is a widely used host for protein production.
- Efficient secretion of recombinant proteins remains a challenge.
- Developing expression systems for native protein forms is crucial for therapeutic applications.
Purpose of the Study:
- To establish an expression system in Bacillus subtilis for producing native human growth hormone (hGH).
- To investigate the secretion efficiency and yield of recombinant hGH (rhGH).
- To analyze the fermentation characteristics influenced by the hGH gene.
Main Methods:
- Constructed a hybrid gene combining a signal peptide sequence from Bacillus licheniformis serine alkaline protease and hGH cDNA.
- Cloned the hybrid gene into a pMK4 vector for expression in Bacillus subtilis under a deg-promoter.
- Analyzed the N-terminal sequence and mass spectrometry of the secreted rhGH.
- Compared fermentation profiles of engineered B. subtilis strains.
Main Results:
- Successfully produced and secreted native-form rhGH from Bacillus subtilis.
- Confirmed proper signal peptide processing by B. subtilis signal-peptidase.
- Achieved a maximum rhGH concentration of 70 mg L(-1) at 32 hours with a yield of 9 g kg(-1) on substrate.
- Observed higher excreted organic acid concentrations in the rhGH-producing strain.
Conclusions:
- The developed expression system effectively mimics serine alkaline protease synthesis and secretion for producing native hGH.
- The approach demonstrates the potential for engineering Bacillus species for heterologous protein production.
- Proper signal peptide processing is key for efficient secretion of recombinant proteins in this system.
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