Optimization of recombinant β-NGF expression in Escherichia coli using response surface methodology

Area of Science:

• Biotechnology
• Molecular Biology
• Neuroscience

Background:

• Human nerve growth factor (NGF) is a neurotrophin with therapeutic potential for neurodegenerative diseases.
• The presence of disulfide bonds in NGF necessitates periplasmic expression for proper folding and activity.
• Escherichia coli offers a viable system for recombinant protein production.

Purpose of the Study:

• To optimize the upstream process for high-yield, biologically active beta-nerve growth factor (β-NGF) expression in E. coli.
• To investigate the effects of induction parameters and cultivation conditions on β-NGF production.
• To confirm the biological activity of the purified recombinant β-NGF.

Main Methods:

• Periplasmic expression of β-NGF in E. coli using the pET39b vector with a DsbA signal sequence.
• Response surface methodology to optimize inducer (IPTG and lactose) concentrations.
• Investigating the impact of postinduction time and temperature on protein yield.

Main Results:

• Optimal β-NGF production achieved with 1 mM IPTG and 0-2% lactose.
• Highest yields obtained at 25°C cultivation temperature and 2-hour postinduction time.
• Purified β-NGF demonstrated comparable cell proliferation activity to standard recombinant human β-NGF in PC12 cell line assays.

Conclusions:

• An optimized upstream process for producing high yields of biologically active β-NGF in E. coli was successfully developed.
• The optimized conditions facilitate efficient recombinant protein production for potential therapeutic use.
• This study provides a foundation for large-scale production of NGF for neurodegenerative disease treatment.