Thermostable Fluorescent Proteins via Destabilizing Insertions
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Solution Overview
Problem
Current methods for stabilizing fluorescent proteins are limited in their ability to maintain functionality at high temperatures, with existing thermostable variants either not achieving sufficient thermal stability or being destabilized by mutations.
Innovation Solution
The development of thermostable fluorescent proteins (TSFPs) through a method involving internal destabilization using heterologous insertions, followed by evolutionary processes to overcome destabilization, resulting in proteins that can retain fluorescence at extreme temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If site-directed mutagenesis is used to stabilize fluorescent proteins, then thermal stability is improved, but fluorescence intensity and solubility are compromised
Solution Approach 1:
The patent introduces destabilizing heterologous insertions into the fluorescent protein structure, which initially reduce stability. This creates selective pressure during evolution that drives the emergence of compensatory stabilizing mutations, ultimately producing proteins with enhanced thermostability while preserving fluorescence functionality.
Solution Approach 2:
The patent employs a two-stage evolutionary process: first introducing controlled destabilizing mutations, then allowing evolution to compensate and improve stability. This preliminary destabilization acts as a catalyst that drives subsequent stabilizing evolution, resulting in proteins that exceed the stability of the wild type.
2Reliability
If conventional fluorescent proteins are used, then fluorescence functionality is maintained, but thermal stability is insufficient for high-temperature applications
Solution Approach 1:
The patent fundamentally changes the stability parameters of fluorescent proteins through evolutionary selection. By subjecting proteins to thermal stress conditions during evolution, the patent selects for variants with altered stability parameters that enable functionality at temperatures exceeding 90°C, while maintaining fluorescence properties.
Solution Approach 2:
The patent allows fluorescent proteins to self-stabilize through evolutionary processes. By introducing destabilizing insertions and then allowing the proteins to evolve under selective pressure, the system automatically generates stabilizing mutations without external intervention, producing thermostable variants that maintain fluorescence functionality.
3Productivity
If heterologous insertions are introduced to destabilize proteins, then evolutionary pressure is increased, but initial protein stability and solubility decrease
Solution Approach 1:
The patent deliberately introduces harmful destabilizing insertions that initially reduce protein stability and solubility. These insertions create strong selective pressure that drives evolution toward compensatory stabilizing mutations, ultimately producing proteins with enhanced thermostability that exceeds the wild type.
Solution Approach 2:
The patent employs preliminary destabilization as a catalyst for evolution. By first introducing heterologous insertions that reduce stability, the system sets the stage for subsequent evolutionary improvement, where compensating mutations arise and result in proteins with superior stability properties.
Data Source
AI summary
Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99° C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80° C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.