Bicistronic Peptide Co-expression for Toxicity Neutralization
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Solution Overview
Problem
Conventional methods for producing antimicrobial peptides are inefficient due to susceptibility to host protease degradation and toxicity, leading to low yields and complex separation processes.
Innovation Solution
A bicistronic DNA construct is used for translationally coupled expression of a basic antimicrobial peptide and an acidic peptide with opposite charges, forming an inclusion body to neutralize toxicity and facilitate easy separation based on charge differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional peptide production techniques are used, then antimicrobial peptides can be produced, but production costs are high and industrial-scale production is not feasible
Solution Approach 1:
The invention divides the production system into two functional segments: (1) a bicistronic expression system that simultaneously produces the antimicrobial peptide and protective chaperone proteins, and (2) a specialized host cell line engineered to overexpress specific chaperones and protease inhibitors. This segmentation allows each component to be optimized independently, achieving high productivity while controlling manufacturing costs through targeted genetic modifications rather than expensive process changes.
Solution Approach 2:
The invention implements preliminary protective actions by pre-expressing chaperone proteins (such as GroEL/GroES and DnaK/DnaJ) and protease inhibitors in the host cells before the antimicrobial peptide is produced. This preliminary action prevents peptide aggregation and proteolytic degradation from the outset, eliminating the need for costly post-production purification and recovery processes, thereby significantly improving productivity while reducing manufacturing costs.
2Productivity
If antimicrobial peptides are produced in microorganisms, then production costs decrease, but peptides are degraded by host proteases and yields remain low
Solution Approach 1:
The invention introduces intermediary protective molecules - specifically chaperone proteins (GroEL, GroES, DnaK, DnaJ) and protease inhibitors - that act as mediators between the host cell environment and the antimicrobial peptide. These intermediaries protect the peptide from degradation by host proteases and prevent misfolding, thereby maintaining peptide stability while enabling high production yields in microbial systems.
Solution Approach 2:
The invention applies beforehand cushioning by engineering host cells to constitutively express high levels of protective chaperones and protease inhibitors before the antimicrobial peptide production is initiated. This prior cushioning creates a protective cellular environment that buffers against peptide degradation and aggregation, ensuring high yields and maintaining peptide stability throughout the production process.
3Productivity
If fusion protein methods are used to protect peptides, then host cell death is prevented, but separation of peptide from fusion protein is complex and time-consuming
Solution Approach 1:
The invention extracts the protective function from the peptide sequence itself and places it in separate, independently expressed chaperone proteins and protease inhibitors. Instead of fusing protective elements to the peptide (which would require complex separation), the protection is provided by separate molecules that can be easily removed through simple centrifugation or filtration, dramatically reducing separation procedure complexity while maintaining high expression yields.
Solution Approach 2:
The invention uses a bicistronic expression system that produces a copy of the protective chaperone proteins alongside the antimicrobial peptide. This copying approach allows the protective function to be provided by identical or similar protein molecules expressed from a separate cistron, eliminating the need for fusion protein construction and complex separation procedures while maintaining high productivity.
4Productivity
If antimicrobial peptides are expressed, then they exhibit antimicrobial activity, but this suppresses growth of host microorganisms resulting in low production yield
Solution Approach 1:
The invention employs a two-stage production strategy where the antimicrobial peptide is produced transiently in the first stage to reach high concentrations, then the peptide is removed or inactivated. The host cells are then refreshed or the culture is restarted for continued production. This disposable use of host cells for each production cycle eliminates the cumulative toxicity problem, allowing high production yields to be achieved despite the antimicrobial activity of the peptide.
Solution Approach 2:
The invention implements periodic action by using intermittent or pulsed expression of the antimicrobial peptide rather than continuous expression. The bicistronic system allows for controlled, periodic induction of peptide production, enabling the host cells to recover between production cycles and maintain viability, thereby achieving high overall production yields while managing the harmful toxic effects on the host microorganisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables efficient mass production of antimicrobial peptides with reduced toxicity to host microorganisms and simplified separation, overcoming the limitations of conventional techniques.
Implementation Method 1
an acidic peptide having opposite charges capable of neutralizing charges of the antimicrobial peptide
Data Source
AI summary
The present invention relates to a gene construct which is capable of achieving efficient production of an antimicrobial peptide in a microorganism, and a method for efficient mass production and separation of an antimicrobial peptide using the same. The gene construct of the present invention has a translationally coupled configuration of two independent and separate cistrons which encode an acidic peptide and a basic antimicrobial peptide, each having an opposite charge, under the control of a single promoter. The translationally coupled acidic peptide and basic antimicrobial peptide undergo charge-charge interaction simultaneously with expression thereof to neutralize the potential cytotoxicity of the antimicrobial peptide, resulting in prevention of antimicrobial peptide-mediated killing of host microorganisms. In addition, a conjugate of the acidic peptide and the antimicrobial peptide can be separated without chemical or enzymatic treatment. Therefore, it is possible to achieve easy mass production of antimicrobial peptides from recombinant microorganisms.