How to trigger periplasmic release in recombinant Escherichia coli: A comparative analysis

Area of Science:

• Biotechnology
• Molecular Biology
• Microbial Engineering

Background:

• Recombinant protein production in Escherichia coli often results in intracellular accumulation.
• Periplasmic protein localization offers an advantage for purification via selective outer membrane disruption.
• Existing methods for periplasmic release often lack differentiation between controlled leakiness and cell lysis.

Purpose of the Study:

• To compare different strategies for triggering controlled protein leakiness from the E. coli periplasm.
• To quantify both leakiness and lysis during these processes.
• To establish an optimized protocol for enhanced periplasmic protein recovery.

Main Methods:

• Testing and comparing various strategies to induce E. coli leakiness during cultivation.
• Quantifying protein leakiness and cell lysis simultaneously.
• Evaluating the efficacy of TRIS incubation and mild heat treatment.

Main Results:

• Incubation with 350 mM TRIS at a constant pH for several hours, followed by mild heat treatment up to 38°C, effectively triggers protein leakiness.
• This optimized method results in minimal cell lysis compared to other tested strategies.
• The study provides a quantitative comparison of different leakiness induction methods.

Conclusions:

• The recommended protocol of TRIS incubation and mild heat treatment is effective for selective periplasmic protein release.
• This approach yields purer crude extracts by minimizing host cell protein contamination.
• The findings provide a robust foundation for future research in optimizing recombinant protein production in E. coli.