Protein Interaction Detection via Fluorescent Focus Multimerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for detecting protein-protein interactions in living cells struggle to provide positional and temporal information about these interactions, often requiring artificial manipulation of proteins and suffering from limitations such as weak luminescent signals, cross-excitation, and difficulty in tracing interactions before and after they occur.
Innovation Solution
The method involves expressing first and second fusion proteins in cells, where the first protein is fused with an association-inducing protein and the second protein is fused with a fluorescent protein having multimerization ability, allowing for the detection of fluorescent foci formed upon interaction, which indicates the association and duration of protein-protein interactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fluorescence reconstitution method is used to detect protein-protein interaction in living cells, then the interaction can be detected in natural environment, but positional and temporal information cannot be obtained
Solution Approach 1:
The patent introduces a third protein (Flag-tagged protein) as an intermediary marker that binds to one of the interacting proteins. This intermediary allows optical tracking of the interaction position and timing without disrupting the natural interaction, solving the information loss problem while maintaining natural detection environment
Solution Approach 2:
The patent utilizes fluorescence color changes and optical properties to detect and track protein interactions. By using fluorescently labeled antibodies against the intermediary protein, the system can visually track interaction positions and temporal dynamics through color signal changes
2Stability of the object's composition
If luciferase reconstitution method is used, then reversible interaction can be detected, but the luminescent signal is weak requiring long exposure time
Solution Approach 1:
The patent creates an optical copy of the interaction event by introducing a third protein marker that can be detected through fluorescence microscopy. This copying approach converts the weak luminescent signal into a stronger fluorescent signal that can be captured with shorter exposure times while maintaining reversible interaction detection capability
3Loss of information
If FRET method is used to obtain positional and temporal information, then interaction dynamics can be tracked, but the system construction becomes complicated
Solution Approach 1:
The patent extracts the complexity of FRET by removing the need for donor-acceptor fluorescent protein pairs and linker optimization. Instead, it uses a simpler third-protein marker system with fluorescently labeled antibodies, achieving the same information gain without the complicated construction requirements
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 enables the detection of protein-protein interactions in their natural intracellular environment, providing both positional and temporal information, and allows for the identification of involved amino acid residues and modulation of interactions by substances.
Implementation Method 1
a fluorescent protein having a multimerization ability
Data Source
AI summary
A method for detecting an interaction between a first protein and a second protein comprises the steps of:expressing in a cell a first fusion protein comprising the first protein and an association-inducing protein, and a second fusion protein comprising the second protein and a fluorescent protein having a multimerization ability;detecting a fluorescent focus formed by an association between the first fusion protein and the second fusion protein in the cell; anddetermining an interaction between the first protein and the second protein according to the detection of the fluorescent focus.