FimGt-DsF Stabilized Complex for N-Terminal Phage Display
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional phage display methods face limitations, particularly in achieving robust N-terminal display of proteins, which is essential for applications requiring a free C-terminus and is not suitable for C-terminal fusion, such as displaying proteins that need interaction or cDNA libraries, due to low display levels and optimization requirements.
Innovation Solution
The use of stabilized protein complexes comprising a first polypeptide chain with a DsF sequence and a second polypeptide chain with a FimGt sequence, enabling N-terminal attachment of proteins of interest to filamentous phages via donor strand complementation, providing a stable and specific linkage for phage display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If N-terminal fusion of proteins to coat proteins is used, then display of proteins requiring free C-terminus is enabled, but display levels are low and optimization is required
Solution Approach 1:
The invention introduces FimGt and DsF as intermediary proteins that mediate the attachment of POI to the phage particle. Instead of directly fusing POI to coat proteins, the POI is fused to DsF, which then binds to FimGt that is incorporated into the phage coat. This intermediary system enables N-terminal display with high efficiency without requiring direct fusion to coat proteins.
Solution Approach 2:
The invention changes the parameters of the display system by using the FimGt-DsF interaction pair with their specific binding characteristics (KD value, binding affinity). By exploiting the specific biochemical parameters of this interaction, the system achieves high display levels through stable binding while maintaining the N-terminal fusion configuration.
2Productivity
If conventional C-terminal display is used, then high display levels are achieved, but proteins requiring free C-terminus cannot be displayed
Solution Approach 1:
The invention inverts the conventional display approach by switching from C-terminal fusion to N-terminal fusion. Instead of fusing POI to the C-terminus of coat proteins, the POI is fused to the N-terminus and attached to the phage via the FimGt-DsF interaction system, thereby enabling display of proteins that require a free C-terminus while maintaining high display levels.
3Ease of manufacture
If direct fusion of POI to coat proteins is used, then simple construction is achieved, but protein activity may be compromised
Solution Approach 1:
The FimGt-DsF interaction pair serves as an intermediary that separates the POI from direct contact with the phage coat proteins. The POI is fused to DsF, which binds to FimGt on the phage surface, creating a buffer zone that minimizes potential interference with POI structure and activity while still achieving stable attachment.
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 approach allows for high-level display and independent translocation of proteins, overcoming the limitations of conventional phage display by enabling N-terminal fusion and maintaining protein activity, especially for enzymes like DNA polymerase, and facilitating the directed evolution of bond-forming and bond-breaking enzymes.
Implementation Method 1
stabilized protein complexes comprising a first polypeptide chain with a DsF sequence and a second polypeptide chain with a FimGt sequence, enabling N-terminal attachment of proteins of interest to filamentous phages via donor strand complementation
Data Source
AI summary
The present invention relates to bacterial pilus protein complex FimGt-DsF stabilized protein complexes for producing phagemids or filamentous phages, and methods for use of these.