Protein Macrocyclization via Trivalent Cross-Linkers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for stabilizing proteins, particularly enzymes, face challenges under harsh conditions such as elevated temperatures and denaturants, and existing approaches like pegylation or introduction of non-proteinogenic amino acids are complex and require multiple optimization rounds.
Innovation Solution
A method involving trivalent thiol-reactive cross-linkers that form covalent bonds with three cysteine residues in proteins, specifically introducing cysteine residues to create stable cross-links without affecting enzymatic active sites, using cross-linkers with specific core structures and linkers to enhance protein stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If covalent protein modifications (e.g., pegylation or glycosylation) are used to increase biostability, then protein stability is improved, but the complexity of the modification process and multiple optimization rounds are required
Solution Approach 1:
The invention divides the protein stabilization problem into specific targeted modifications at three cysteine residues rather than general surface modifications. The trivalent cross-linker is segmented into three reactive arms that independently target specific cysteine residues, allowing precise control over the modification pattern and reducing optimization complexity.
Solution Approach 2:
The invention applies modifications locally at three specific cysteine residues rather than general surface modifications. This localized approach at strategically chosen positions creates macrocyclic structures that specifically stabilize the protein core without requiring extensive optimization of general surface properties.
2Stability of the object's composition
If directed evolution, consensus-based mutagenesis or computational approaches are applied to improve protein core interactions and structure rigidification, then protein stability is improved, but multiple rounds of optimization are required
Solution Approach 1:
The invention performs preliminary action by pre-selecting three cysteine residues at strategic positions within the protein sequence before any stabilization attempt. This pre-planned macrocyclization strategy eliminates the need for multiple rounds of directed evolution or computational optimization, as the three-cysteine framework is designed to provide immediate structural rigidification upon cross-linking.
3Stability of the object's composition
If trivalent thiol-reactive cross-linkers form covalent bonds with three cysteine residues, then protein stability is significantly increased, but the protein must be modified to introduce exactly three accessible cysteine residues
Solution Approach 1:
The invention changes the parameter of cysteine residue count from the native protein state to exactly three cysteine residues at specific positions. This parameter change is achieved through site-directed mutagenesis to introduce cysteines at strategic locations, and the trivalent cross-linker is designed with three reactive arms to match this three-cysteine configuration, creating a stoichiometrically balanced reaction that simplifies the manufacturing process.
4Temperature
If cross-linkers with specific core structures and linkers are used to enhance protein stability, then melting temperature is elevated, but the cross-linker must be designed with specific structural parameters
Solution Approach 1:
The invention creates a universal trivalent cross-linker platform with a central core and three identical or varied arms that can target different cysteine residues. This multi-functional design allows the same cross-linker scaffold to be used across different protein targets, reducing the need for custom-designed cross-linkers for each application while maintaining the ability to elevate melting temperatures through appropriate linker length and chemistry selection.
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
The method significantly increases protein stability, as demonstrated by elevated melting temperatures and resistance to denaturants, while maintaining enzymatic activity, particularly evident in Sortase A and KIX domain polypeptides, allowing for effective protein function under conditions where wildtype enzymes fail.
Implementation Method 1
contacting said protein with a trivalent thiol-reactive cross-linker such that the linker forms covalent bonds with each of the three cysteine residues
Data Source
AI summary
The present invention relates to methods and cross-linkers for the macrocyclization of proteins. The invention is useful for increasing the stability of a protein.