N-Terminal Protein Modification via Aminoacyl tRNA Transferase
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Solution Overview
Problem
Current methods for N-terminal protein modification often require prior protein manipulation, denature the protein, or involve complex synthesis, limiting their efficiency and specificity, especially for maintaining protein folding and activity.
Innovation Solution
A chemoenzymatic method using aminoacyl tRNA transferases, such as E. coli AaT, to modify the N-terminus of proteins with non-natural or natural amino acids as adenosine esters, allowing for efficient modification under mild conditions without significant protein denaturation, and enabling traceless protein ligation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional chemical methods are used for N-terminal modification, then modification can be achieved, but side reactions occur and specificity is reduced
Solution Approach 1:
The patent employs aminoacyl tRNA transferases as intermediary enzymes to mediate the transfer of amino acids from aminoacyl-tRNA to the protein N-terminus. This enzymatic intermediary system provides high specificity for N-terminal modification while avoiding the side reactions associated with conventional chemical methods. The transferase enzyme acts as a selective mediator that recognizes both the aminoacyl-tRNA and the protein N-terminus with precision.
Solution Approach 2:
The patent replaces conventional chemical modification methods with an enzymatic mechanism. Instead of using chemical reagents that can cause multiple side reactions, the invention uses aminoacyl tRNA transferases to catalyze the transfer of amino acids. This substitution of chemical mechanisms with enzymatic mechanisms provides superior specificity and eliminates harmful side reactions.
2Ease of manufacture
If prior protein manipulation is performed to enable modification, then modification can be achieved, but protein folding and activity are compromised
Solution Approach 1:
The patent enables the protein to modify itself at its N-terminus through the action of aminoacyl tRNA transferases. The enzyme system works on the native protein structure without requiring prior manipulation, unfolding, or denaturation. The protein's own N-terminal amino groups serve as the reaction site, allowing modification to occur in a self-service manner that preserves the protein's folded state and activity.
Solution Approach 2:
The patent changes the reaction conditions to occur under mild physiological parameters rather than requiring extreme conditions for protein manipulation. The aminoacyl tRNA transferase catalyzed reaction proceeds under gentle conditions that maintain protein folding, avoiding the need for denaturing agents or extreme pH/temperature conditions that would compromise protein structure.
3Productivity
If high protein concentrations are used to drive modification reactions, then modification efficiency improves, but protein aggregation and denaturation increase
Solution Approach 1:
The patent changes the concentration parameter to work effectively at low protein concentrations. The aminoacyl tRNA transferase system has high catalytic efficiency and can drive modification reactions to completion even when protein concentrations are low, eliminating the need for high concentrations that cause aggregation and denaturation.
Solution Approach 2:
The patent replaces concentration-driven chemical reactions with enzyme-catalyzed reactions. The aminoacyl tRNA transferase provides catalytic acceleration that allows modification to proceed efficiently at low substrate concentrations, replacing the need for high concentrations that would otherwise be required to drive the reaction.
4Adaptability or versatility
If complex synthesis methods are used for N-terminal modification, then diverse modifications can be achieved, but process complexity and time increase
Solution Approach 1:
The patent employs aminoacyl tRNA transferases that can accept various different amino acids and aminoacyl-tRNA molecules as substrates. This universal enzyme system can catalyze the transfer of diverse amino acids to protein N-termini using a single enzyme type, providing versatility in modification chemistry while avoiding the complexity of multiple specialized synthesis pathways.
Solution Approach 2:
The aminoacyl-tRNA serves as a universal intermediary carrier that can deliver different amino acids to the transferase enzyme. This intermediary system provides a simplified two-component approach (enzyme + aminoacyl-tRNA) that can achieve diverse modifications without requiring complex multi-step synthesis procedures for each different modification.
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 high-yield N-terminal modification of proteins at low concentrations, maintaining protein folding and activity, and facilitates traceless protein ligation, expanding the scope of protein modification and conjugation techniques.
Implementation Method 1
A chemoenzymatic method using aminoacyl tRNA transferases, such as E. coli AaT, to modify the N-terminus of proteins with non-natural or natural amino acids as adenosine esters
Implementation Method 2
The transferase transfers the amino acid from the adenosine donor to the N-terminus of the protein
Data Source
AI summary
The invention includes a selective method of modifying the N-terminus of a protein using an aminoacyl tRNA transferase. In certain embodiments, the method comprises contacting a solution of the protein or peptide with a transferase and a derivative of a molecule, whereby the N-terminus of the protein or peptide is derivatized with the molecule.