Engineered DNA Polymerases for Fast Isothermal Amplification
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Solution Overview
Problem
Current DNA amplification techniques, such as PCR, require high temperatures and expensive equipment, while isothermal amplification methods like LAMP are limited by the capabilities of existing Bst DNA polymerases, which lack enhanced functionality like fast reaction times, low background activity, and thermal stability.
Innovation Solution
Engineered DNA polymerases with amino acid sequences at least 80% identical to specific sequences (SEQ ID NO:4, 5, 6, 24) or 92% identical to other sequences (SEQ ID NO:2, 3) are developed, offering improved properties such as fast reaction times, low background activity, and enhanced thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If isothermal amplification using Bst DNA polymerase is employed, then expensive thermal cycler equipment is eliminated, but reaction time increases and thermal stability is insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the amino acid sequence of Bst DNA polymerase through site-directed mutagenesis. Specific residues were mutated to alter the enzyme's catalytic efficiency and thermal stability parameters, achieving faster reaction times and improved temperature resistance while maintaining isothermal functionality
Solution Approach 2:
The patent discards the limitation of original Bst polymerase thermal stability by removing specific amino acid constraints through mutation. The engineered polymerase recovers and extends thermal stability beyond the parent enzyme, enabling use at higher temperatures without requiring thermal cycler equipment
2Adaptability or versatility
If Bst DNA polymerase is used for isothermal amplification, then strand displacement capability is achieved, but background activity remains high
Solution Approach 1:
The patent applies local quality by making targeted mutations at specific locations within the polymerase active site and regulatory regions. These localized amino acid changes modulate the enzyme's strand displacement activity and background incorporation rates, optimizing performance for isothermal amplification while reducing spurious background signals
3Productivity
If engineered DNA polymerases with enhanced functionality are developed, then reaction speed and thermal stability improve, but protein engineering complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the protein engineering task into discrete, manageable steps: (1) identifying target amino acid positions based on structural modeling, (2) performing site-directed mutagenesis at specific residues, (3) expressing and purifying individual mutant variants, and (4) characterizing their functional properties. This segmented approach simplifies the overall engineering complexity while achieving enhanced reaction speed and thermal stability
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 engineered DNA polymerases demonstrate superior performance in DNA amplification, including faster reaction times, reduced background activity, and maintained activity at high temperatures, thereby enhancing the capabilities of isothermal amplification techniques.
Implementation Method 1
Bst DNA polymerases are enzymes that can copy DNA or RNA strands and have a robust ability to separate the resulting duplexes and displace the upstream strand during synthesis
Implementation Method 2
Bst DNA polymerases are enzymes that can copy DNA or RNA strands and have a robust ability to separate the resulting duplexes and displace the upstream strand during synthesis
Data Source
AI summary
Provided herein is an engineered DNA polymerases containing an amino acid sequence selected from: an amino acid sequence that is at least 80% identical to an amino acid sequence selected from: SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, and SEQ ID NO:24; and an amino acid sequence that is at least 92% identical to an amino acid sequence selected from: SEQ ID NO:2 and SEQ ID NO:3. Also provided are methods employing the described DNA polymerases.