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Published on: March 6, 2013
Stabilization of a proteolytically sensitive cytoplasmic recombinant protein during transition to downstream
1Department of Biochemistry and Biotechnology, Royal Institute of Technology (KTH), Stockholm, Sweden. aleksei@biotech.kth.se
Biotechnology and Bioengineering
|February 10, 1999
Summary
To stabilize recombinant protein A in Escherichia coli, deplete intracellular ATP by removing oxygen and glucose. This significantly enhances protein stability during downstream processing.
Area of Science:
- Biotechnology
- Molecular Biology
- Protein Chemistry
Background:
- Recombinant protein A stability is crucial for efficient downstream processing.
- Intracellular conditions during the transition from fed-batch to downstream processing impact protein stability.
- Adenosine triphosphate (ATP) levels are implicated in protein degradation.
Purpose of the Study:
- To investigate the impact of aeration and glucose feeding on recombinant protein A stability in Escherichia coli.
- To correlate intracellular adenosine triphosphate (ATP) pool levels with protein A stability.
- To identify optimal conditions for minimizing proteolysis during downstream processing.
Main Methods:
- Fed-batch cultivation of Escherichia coli expressing recombinant protein A.
- Manipulation of aeration (aerobic vs. anaerobic) and glucose feeding conditions.
- Measurement of intracellular ATP, ADP, and AMP concentrations.
- Assessment of protein A stability during simulated downstream processing steps.
Main Results:
- Absence of oxygen and glucose led to a significant decrease in intracellular ATP (<0.5 mM) and near-complete stabilization of protein A.
- Interruption of feeding under aerobic or anaerobic conditions with glucose did not fully stabilize protein A.
- Sulfite-induced anaerobic conditions further reduced ATP levels and enhanced protein A stabilization.
- Increased ADP and AMP concentrations correlated with protein A stabilization.
- ATP depletion during downstream processing (harvesting, centrifugation, cell disruption) was observed.
Conclusions:
- Depletion of the intracellular ATP pool is a key factor in stabilizing recombinant protein A in Escherichia coli.
- Controlling oxygen and glucose availability is critical for managing ATP levels and protein stability.
- While ATP is a factor, other unknown factors limit proteolysis in vitro, suggesting complex regulation.
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