Engineered T4 DNA Ligase Mutants for High-Efficiency Ligation
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Solution Overview
Problem
Current T4 DNA Ligase enzymes have limitations in terms of activity, requiring higher concentrations and longer times for effective ligation reactions, which can be inefficient in molecular biology applications.
Innovation Solution
Engineered T4 DNA Ligase mutants with specific amino acid substitutions, such as E23K, E88K, and others, exhibit enhanced ligation activity, allowing for more efficient DNA ligation at lower concentrations and reduced reaction times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wild-type T4 DNA Ligase is used, then ligation reactions can be performed, but higher enzyme concentrations and longer reaction times are required, reducing efficiency
Solution Approach 1:
The patent applies parameter changes by modifying the amino acid sequence of T4 DNA ligase through site-directed mutagenesis. Specific residues (such as E23, E88, K98, E132, E143, E173, E240, E271, K306, E321, D340, D371, E438, E440) are mutated to improve catalytic activity. This changes the enzymatic parameters to achieve faster ligation rates and higher efficiency at lower concentrations, directly resolving the contradiction between productivity and time loss.
2Productivity
If wild-type T4 DNA Ligase is used, then ligation reactions can be performed, but higher enzyme concentrations are required, increasing cost and reducing efficiency
Solution Approach 1:
The patent modifies the enzymatic parameters of T4 DNA ligase through amino acid substitutions. The mutated enzymes exhibit enhanced specific activity, allowing effective ligation reactions at lower enzyme concentrations. This directly addresses the contradiction by changing the quality parameter (enzyme activity) to reduce the quantity parameter (enzyme concentration) needed for equivalent productivity.
3Productivity
If engineering mutations are introduced to increase activity, then ligation efficiency improves, but enzyme structure and stability may be affected
Solution Approach 1:
The patent applies local quality by introducing specific point mutations at particular amino acid positions in the T4 DNA ligase sequence. Rather than globally altering the enzyme, localized changes are made at catalytically important residues (e.g., E23K, E88K, K98E). This allows improvement of ligation activity at specific functional sites while preserving the overall structural integrity and stability of the enzyme molecule.
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 mutants demonstrate increased activity compared to wild-type T4 DNA Ligase, enabling faster and more efficient ligation reactions with reduced enzyme requirements, thus improving molecular biology workflows.
Implementation Method 1
T4 DNA Ligase is a versatile enzyme that catalyzes the bond joining duplex DNA or RNA at both cohesive ends and blunt ends
Implementation Method 2
Ligases are commonly used in molecular biology for forming phosphodiester bonds between duplex nucleic acid fragments at the intersection of juxtaposed 5′ phosphate and 3′ hydroxyl termini
Data Source
AI summary
The invention includes a mutant T4 DNA ligase or a biologically active fragment thereof, which has greater activity than wild type T4 DNA ligase. The mutant T4 DNA ligase, or the biologically active fragment, has one or more substitutions differing from the wild type, as described more fully in the Summary with reference to the Sequence Listing.